Mobile app development - the ultimate guide

This article sums up everything you need to know about mobile app development. Are you wondering about the development process, cost or most common mistakes? Wonder no more - you will find all the answers in this ultimate guide to the world of creating mobile apps.
Looking for app developers?
mobile app development
app development guide
A cheatsheet for everyone who strives to understand mobile app development:
- startup founders,
- managers of companies aiming to innovate,
- dreamers with new app ideas.
In other words, if you’re not a mobile app developer yourself but you need to understand this area, this guide was tailor-made for you. Welcome to our ultimate cheatsheet that will allow you to make sense of the different aspects of app design and development.
If you encounter some parts that are a bit too difficult to comprehend or too trivial for you, no worries! Just skip to the next section :-)
What is a mobile app?
That’s a very trivial question, you might think. Well, you may be correct, but just so that we are on the same page from the start:
A mobile app is a software (or a program) that runs on a mobile phone. It is designed for use on mobile phones and tablets. Mobile apps today run on operating systems (OS) Android and iOS.
Android - the most wide-spread OS by Google, used by the vast majority of today’s smartphones
iOS - Apple’s OS, the backbone of iPhones and iPads
Other - Windows Phone by Microsoft is not receiving security updates anymore, it would be pointless to develop apps for it now
Mobile apps can take many shapes and forms, ranging from games to eshops and communication platforms. You can find apps for both platforms in their respective app marketplaces - Google Play for Android and AppStore for iOS.
What are the most well-known mobile apps? You might have heard of WhatsApp, Uber or Spotify. As you can see, apps can establish themselves in many different domains.
Why should you develop an app?
Mobile apps have triggered major shifts in consumer behaviour, business models and the core principles of various industries. Why? Because when combined with smartphones being omnipresent in customers’ pockets, mobile apps empower people to conveniently communicate, order services and purchase goods regardless of their location.
why to develop an app
World-famous apps,
that changed their industry
Mobile apps have the potential to become the gamechangers of their fields, bring down the well-established brands and catapult the new players to the lead. It’s an absolutely crucial technology if you:

- want to innovate your business,
are seeking a way to improve or change the standards in your field,
empower your customers with a new tool.
Moreover, the amount of time we spend hooked to our smartphones and in our apps keeps rising. Website browsing on mobiles is on a steep decline. Smartphone penetration has reached even poor communities in much less developed regions. Here are some interesting facts and numbers:
🌍 Over 3 billion people worldwide use smartphones, more than 1.5 billion use tablets
⏳ We spend 90% of our mobile time in apps
📲 Every day, over 700 million apps get downloaded from app stores
Most common mistakes
during app preparation

Before you delve into app development, double-check that you’re not about to make one of these common mistakes which often lead to disappointing results and wasted resources:
1. Your concept is not original enough
Don’t create an app only because everyone else has one. Identify the added value that the new app should generate for your customers. Write down the app’s unique selling points. And think about other platforms that might be more suitable for your plans.
2. You don’t have a business plan
Every project needs a quality business plan. A mobile app is no exception. The app market is saturated with experienced players who know how to get things done efficiently. Make sure to invest enough effort into careful planning.
3. Your budget is not sufficient for a quality product
Mobile app development costs a lot of money (we’ll cover that later). Therefore, you need to have substantial resources at hand for both development and subsequent maintenance. The necessary investments generally revolve around tens of thousands of pounds at least. If you invest less and take an amateurish approach, chances are the app won’t be successful.
4. You’re not thinking about marketing
The mobile app industry is highly competitive these days. It would be very naive to think that the app will find its way to users without your action. You need to have both a promotional strategy and an adequate marketing budget dedicated to the app project.
5. You overestimate your capacities
Even if you choose the most suitable agency, app development is a demanding process. Make sure to book enough capacities for intensive collaboration, meetings, workshops and planning.
6. Your idea has not been validated
When we really into something, we tend to miss some of the pitfalls. That’s why concept validation is so crucial. Make sure you test your ideas before bringing them to life. The first step is creating a prototype and testing it with real users - do they like it? Would they use the app?
7. You underestimate your competitors
Invest a lot of effort into preliminary market research to discover any alternative solutions that already exist. Or perhaps existed before but are out of business now. Try to find out why and learn from their mistakes.
8. You’re focussing solely on the app
Mobile apps can be amazing assets to your business but there are very few projects which could be built exclusively on an app. You will most likely also need a back-end, promotional website, perhaps even a web version of your app or technical support.
9. You think it will all end with the launch
It’s highly unlikely that your app won’t require any additional effort after the launch (especially if it’s successful). One could say that mobile app development is a never-ending process. Make sure you maintain the app correctly and apply further iterative development - we will zoom in on that later.
interni vyvoj nebo agentura
In-house, or agency?
We can't give you a clear cut answer to this dilemma. It largely depends on the type of your business. Building an in-house team will be a smart choice for your project if:
- you are a tech company,
- the app will be the core of your business,
- the project will generate sufficient workload to employ a stable team of developers and managers,
- your budget for maintenance and operations reaches hundreds of thousands of pounds.
Contrarily, teaming up with an agency will be the favourable move if:
- your business rests on other pillars than the app,
- you're not a tech company,
- there's no need to employ the whole team on a full-time, permanent basis,
- you want to be flexible with your maintenance and operations cost.
app development technology
Programming language constitutes means of communication between a computer and a programmer. It's a tool for defining and recording algorithms that the computer should execute. The programmer writes an entry to define a solution to a problem at hand. The computer then interprets this definition by using various technologies.
Front-end is the presentational layer of an app. You could think of it as the part of the app which is seen by users. The front-end part of an app handles the displaying of particular data which are stored and processed in the app.
Back-end refers to the inner layer of the app, the one which is not seen by the user. It processes the entries of user data, stores it in databases and modifies it. Back-end is also responsible for communicating with the APIs of external services, for instance.
Hybrid, or native?
Every programmer has a slightly different opinion on this. Hybrid apps rely on the power of an internet browser. Native apps use the processor of the smartphone directly. Hence, native mobile apps tend to perform better. However, their development requires more time and resources. Let's take a look at the main differences between hybrid and native mobile app development:
hybridní nebo nativní vývoj aplkace
Pros and cons,
of native and hybrid app development
It's impossible to say which approach is better overall - the decision must be built on a careful consideration of each projects specifics. But here are a few general hints for deciding if the type of your project is more suitable for hybrid or native:
Consider hybrid development if:
- you want to rapidly test an idea for an app and the final production version can be realized later on
- it's a fairly simple app in terms of inputting and processing data
- the app will run on a small number of devices (app for internal use)
- the app will only be used for a limited amount of time (a festival or conference)
Choose native development if:
- your app needs to run fast and smooth also on older devices
- you plan to include animations or other demanding design elements
- perfect user experience is of the essence
- it's a game, augmented reality app, photo or video editor etc.
Which technology is most suitable for you?
Again, it's impossible to give you a clear general conclusion stating which technology or framework is the best. If someone claims otherwise, be cautious - they're most probably not being honest. Every project has its specific characteristics and requires a slightly different approach.
What are some of the most wide-spread technologies?
This programming language serves to develop native apps for Android. Java is generally known for its robustness and wide variability. Kotlin is a new language running in Java Virtual Machine, however, it's definitely easier and faster to learn compared to Java.
This language is perfect for developing native apps for iOS. Swift is a direct product of Apple, it was created to help programmers diminish errors.
A software development kit (SDK) which enables multi-platform development. Flutter enables programmes to compile the final app without any changes to native codes for both Android and iOS. It's a rather new technology by Google, the programming language in use in this case is Dart 2.
React native
This is a hybrid framework by Facebook. It enables programmers to create apps for both Android and iOS. The app logic is programmed with JavaScript/TypeScript. The displaying of the app is based on native components.
Apache Cordova
Another hybrid framework, this time developed by software foundation Apache. The displaying of the app runs solely on web technologies. The app then operates by virtue of WebView which is integrated in the frameworks core and runs the app as a fast web application.
metodika vývoj aplikací
Development methodology
In short, a methodology encapsulates the approach or process of development. Agile methodologies are the most popular ones these days. However, once again, you should first consider which approach suits you and your project before choosing a supplier with a specific methodology. Agile management is suitable for most projects as it enables:
- prompt reactions to changes and market developments,
- fast delivery,
- clear overview of the projects progress,
- clear overview of the projects progress,
- less of a commitment from you as the client.
However, some projects simply don't allow for agile development. That's the case if:
- you have an absolutely precise specification with every detail thoroughly defined,
- the app only makes sense for you as a whole with all the features and details,
- you won't have time to participate in the development process,
- there will definitely be no changes made to the initial specification.
Such a situation is highly unlikely though. In most cases, as a startup or a new digital product, it will be in your interest to be as lean as possible. And we strongly support that! What does it mean to be lean?
Get done as little as possible. Test the product, collect feedback, analyze data and get back to work.
pojmy vývoj moblních aplikací
If you decide to take the agile development approach, you should familiarize yourself with the following terms:
MVP - minimum viable product. The most basic version which allows you to test the app with real users and launch it in app stores.
Release - versions of the app. In order to reach your MVP, you will most likely need to go through a lot of releases. Each release will entail one small piece of the puzzle. Releases should always be functioning and testable.
Roadmap - a plan of work, launches of the respective releases
Backlog - a list of app features that you want to create. Some of them might be very clearly defined, others may only be listed as rather general ideas and can be specified later on
Mistakes you should avoid
Neglected documentation
Thorough documentation is critical for you as the client. Why? Because documentation greatly facilitates the process of one developer handing their responsibilities over to a colleague within the team, or the switch to another agency. If your project is not sufficiently documented, a transition to another supplier will become virtually impossible or at least very costly.
Beware of one common mistake - your documentation shouldn’t be written at the end of the project! It's crucial to document every single feature continually as the project proceeds.

Poor communication
The stumbling block of the majority of unsuccessful projects is a misunderstanding. The developers often don't truly understand the business, and the client doesn't understand the development process. Make sure you adhere to these two basic rules:
- never assume that something is a matter of course
- if something needs to be part of the app, let your developer know
Slow reactions to problems
If a project is not moving forward as expected, it's important to start making changes immediately. Delayed releases indicate a systemic problem. If you count your delay in months now, something went terribly wrong. Act firmly and at this very instant. Don't allow the problems to steal away your projects energy.
Missing the deadlines
This applies to both parties. Mobile app development is a costly and complex process. Every delay can disrupt the plan you prepared. Keep an eye on your developers pace but make sure to apply similarly strict lenses to yourself.
How to choose an agency
for mobile app development?

If you decide to team up with an agency, you should consider the following aspects:
1. Team and experience
Hire a stable, well-coordinated and experienced team. The time needed for new team members to get used to each other goes to months. And you definitely don't want your project facing the risk of a poorly integrated team. Another important point is that your project shouldn't be outsourced to a third party.
2. Technology
Choose an agency that can choose the most suitable technology for your particular project, its scope and objectives and recommend you the most cost-effective approach. The right agency should have experience with technologies that are optimal for your mobile app.
3. References
The agency should have many positive references available, that's a matter of course. Browse through the projects that resemble your app, check the ratings in app stores and ask the agency about measurable results. Don't focus just on the looks of the app, think about the added value it generated for the client.
4. Management
People who manage the project and coordinate all the work are as important as programmers and designers. Therefore, your partner should have a clear project management methodology and should be able to present it to you in an understandable manner.
5. Quality assurance
The quality should be double-checked at every step of the app development roadmap. We're not talking only about manual testing but also everything else from unit tests to prototype testing, code reviews and automated tests.
6. Partnership
Do you need a reliable supplier that will deliver precisely what you ask for - but nothing more? Or are you looking for a more strategic partner who will guide you throughout the whole app development process and will invest a lot of additional energy and thoughts into the project?
Mobile app development cost
Clients often ask designers and developers for very accurate estimates of the final price based just on a brief description of an app. However, when calculating all the costs, many different variables come into play and it's generally not possible to predict the exact final price already in the design and prototyping phase.
app development costs
8 key factors
determining total app cost
1. Availability
On which devices and operating systems should the app run? You should first decide if you want to create a product for iOS, Android or both. The Flutter technology enables developers to save some of the expenses when developing an app for both Android and iOS.
The costs will also differ based on your choice of the supported versions of the operating system(s). Nevertheless, since most users update their OS to the newest version within a few weeks from the release, you can focus mainly on the latest version, especially when developing an iOS app.
2. Complexity of features
One of the crucial determinants of the total cost is definitely the scope and complexity of your app's features. The basic functionality is often accompanied with the following extra features:
- back-end infrastructure
- messages or chat
- push notifications
- activity tracking
- in-app purchases via payment gate
- features utilizing the hardware of the phone
- app personalization based on machine learning
- managing the app and data via web app interface
- advanced data processing methods
- social media integration
- using camera or microphone
When developing a brand new mobile app, the ideal approach is to start with a basic version offering only the most fundamental features (MVP) and then add the additional nice-to-have features one by one in the subsequent phases of the project. This is because such features can substantially slow down the development process and increase the total cost of the app.
3. Design
Mobile app design doesn't entail merely the visual looks of the user interface (UI). Instead, the most demanding part of this phase includes designing the whole product in terms of functionality and navigation, the so-called user experience (UX).
Ideally, the project should start with a series of Design Sprint, week-long intensive blocks of work focused on UX design. The sprints will produce the ideal prototype, already tested with end users. The investments necessary for this phase are again determined by the scope of the app and the target level of thoroughness you wish to ensure for preparations of the UX.
The visual side of the app can be based on the basic system design in order to save some expenses. However, it can also include a unique tailor-made graphic elements or even highly demanding features such as animations or special real-time depictions of data.
4. Manipulation with data
Will the app enable users to make video or voice recordings and take pictures? Your calculation of the total cost should also include monthly or yearly costs of a cloud-based data storage which can be surprisingly costly if the amount of data stored gets becomes very large.
The speed of storing and downloading data can be crucial for certain types of apps. If this is your case, don't try to save money on the storage service.
Another important factor in this category is security. If your app has to handle confidential data such as personal payment history or sensitive business information, you should definitely invest in a cloud solution which guarantees perfectly safe data storage.
5. Administration
The project will further grow if your mobile app needs to implement a Content Management System (CMS) or Customer Relationship Management (CRM) solutions. If you haven't used any CMS or CRM before and the existing licensed third party solutions are not a good match for your project for some reason, it might be a smart decision to develop a custom CMS or CRM from scratch.
6. Team
The number of people in the development team is dependent on the required features and chosen design approach.The basic team includes a project manager, UX designer, tester, at least two developers and sometimes also a dedicated back-end developer. More complex projects require more developers, some of whom can also primarily focus on iOS or Android.
The total cost will also largely depend on the location and pricing of your partnering agency. For instance, a recent comparison indicated that the hourly rates of US developers can be as much as five times higher than the rates of east-european developers and further to the East.
7. Testing
Avoid trying to save expenses on this part of the project. Thorough testing of the final product will dramatically increase your app's quality, speed up the development process and save your some costs related to further adjustments in the future. Make sure to book sufficient capacities for this task.
If you are about to create a very complex app with many demanding features, you should include testing in the planning of the respective sub-phases of your project to prevent the cumulation of bugs and errors in the long run.
8. Support and further development
Last but not least, don’t forget to take into account the long-term costs of maintenance, adjustments to the app, data management and cloud services, launching several updates and offering continuous support to users. And mind that the promotion of the app will cost you something too.
The total mobile app development cost simply cannot be estimated based on a one-sentence description. However, we prepared three basic examples with estimates of required hours of work so that you could make a clearer picture of the overall financial demands of app development.
Estimating app development demands
Basic app
Simple system design, no integration of third party services, no advanced features or back-end for data processing and content management. An app like this would require around 100-130 hours of work.
Moderately complex app
This app has both custom design and more advanced features such as chat, social media integration or payments via a payment gate. Its back-end infrastructure allows admin to efficiently process data. The demands will probably fit somewhere between 500 and 850 hours.
Very comprehensive app
Imagine the previous example with additional animations, ability to process and edit multimedia content, opportunity to tailor the user interface based on machine learning and detailed content management and advanced data processing enabled by complex back-end. This app will definitely require more than 900 hours.
The process of
mobile app development

You have already decided that you will develop an app. And you’ve also teamed up with a suitable development partner by now. But how should the whole development process ideally look like?
Here are the most common approaches you can take when initiating your development:
1. Proof of concept
The first step of app development doesn’t always concern the app itself. Are you not absolutely convinced that there will be a demand for your digital product? Think of a simple way to confirm that the app will have a sufficient target audience with interesting potential. You can save yourself considerable amounts of resources by doing so.
How to test your concept?
Find out what are the responses to the proposed app and if your target group identifies the problem which you aim to solve as an important one. You could create a simple landing page, documents available for free download or a mailing campaign.
Our client wished to test the concept of an app for loan applicants. We created a website which promoted the app and then we ran a PPC campaign. We asked visitors to subscribe to our mailing list to stay up to date about the app’s launch. This way, we collected data that served for assessing the demand for the app.
2. Defining an MVP
You’re rich on ideas but your app only has a very rough outline? Are you struggling to identify the key added value of the app and decide on the features which should be included in the first version? Start with defining your MVP.
How to do that?
The ideal tool for defining an MVP is a design sprint. It’s a week-long (or multiple weeks in a row) sequence of workshops with all relevant stakeholders of the app which result in designing and testing a prototype with real users.
3. Validated prototype
You already have a clear image of the app in your head but you are curious about the opinion of users? Create an interactive prototype which looks exactly like the final product, organize a testing session with potential users and acquire invaluable feedback.
4. MVP development
The app is clearly defined, you are completely sure about its added value and your return on investment. It’s time to kick off the development phase. What can you expect?
- following a roadmap and planning releases
- attending reviews, giving the team feedback during design sprints
- (dis)approving of changes and adjustments made on the way
- receive the final product, coordinate follow-up steps with your marketing team
5. Iterative development
We’ve already discussed the importance of being as “lean” as possible and proceed one small step at a time. In most cases, that means the development process will not end with the app’s launch. Contrarily, there will still be plenty of tasks to cover, such as:
- evaluating the app’s performance and user behaviour
- maintain the roadmap and backlog
- plan further releases
- coordinate the app’s maintenance and updates with your other activities
Promoting your
mobile app

Successful testing and final launch definitely call for a celebration, however, this is also the time when you need to give your app a very strong push on its journey to the hearts of your target audience. The process of promoting your mobile app can be divided into two main phases - before and after launch. The section below will present an overview of the fundamental marketing strategies which can help you get the app to real end users.

Promotion before launch:
1. Appealing and functional landing page
Make sure that your landing page conveys the key message in an attractive format which sparks interest in its visitors. Offer users the possibility to subscribe to your newsletter in order to stay up to date regarding the app’s official launch.
2. Influencer marketing
Work with relevant communities or team up with individuals that have wide and relevant reach on social media or attract many visitors to their blog. Offer them exclusive access to the app prior to launch and motivate them with incentives to write and share a positive review.
3. Cooperate with the media
Depict a catchy story around the app or at least define exactly how the app will disrupt the market or make users’ life much easier. Use this material to address the media in the form of a press release or an interview offer. If you don’t receive positive answers, consider paying for native advertisements in online media which could generate interesting traffic for your landing page and raise awareness of the app.
4. Content marketing and SEO
Start creating unique content that is useful for your target group and clearly linked to the mission of your app. In the first phase, focus on communicating the reasons why the app is being developed through articles or video content. Generate interest and attract attention. After the launch, offer users content which nicely complements the app.
5. Visibility in app stores
Make sure the app will be perfectly visible in App Store and Google Play. Its page needs to be visually appealing - offers users attractive and informative screenshots. Apply the SEO principles when writing the app’s description.
6. Guerilla campaign
Get the attention of the general public by virtue of an innovative activation on the streets. Don’t forget that there always needs to be a match between your activities and the app, its brand and value proposition.
What do the experts say
about mobile app promotion?
Anya Gair
Anya Gair

SEO Executive at Yellowball
Improving your rankings on Google Play and Apple App Store is vital for your app being found. You could have the most user-friendly, beautifully-designed app, but if it's not ranking highly on app stores users aren't going to find it. This means that they won't be downloading it either, and therefore it won't be generating your any revenue or traffic. To improve the visibility of your app on the app stores, you need to do ASO (app store optimisation).
This is like App SEO, whereby you tailor different elements of your app store landing page to improve your app's ability to rank. To do this, you need to find out what terms users search with on the app stores (keyword research) to find apps like yours, and then carefully choose which keywords to target in your the app URL, app title, keyword field (IOS only), description. You should also ensure that your imagery & videos is optimised to improve conversions, as these are the first things users see when they click on your app.
Read more in this detailed guide on ASO.
Promotion after launch
1. Social media advertising
80% of our social media browsing happens on mobile phones erefore, social media offer vast potential for your app promotion and are possibly the absolute best location for your ads.
Invest into the making of a quality promotional video, create attractive visuals and carefully choose the target audience for this phase of the campaign. Don’t forget about a salient Call-to-Action button leading straight to App Store or Google Play.
2. Rewards for inviting friends
Of all the marketing channels out there, people trust personal recommendations from friends and acquaintances (Word of Mouth) the most.
Make the most out of this. Offer active users attractive incentives for every new user they manage to bring to the app.
3. Community management in app stores
Maintain a lively positive conversation with your app’s users. Answer the questions and react to the reviews in App Store and Google Play.
Respond to negative comments with gratitude and implement the feedback in future versions of the app.
4. Mobile app contests and awards
Nominate your app for mobile development awards and contests relevant to the app type and focus.
Small contests can equip you with at least another positive reference for your web, more popular app awards can generate interesting publicity and attract the attention of both media and potential users.
5. Banners and Call-to-Action buttons on partnering websites
Form partnerships with other websites to increase the flow of users to your app’s page on App Store and Google Play.
We tend to browse websites mostly on mobiles these days. web browsing happens in mobile phones today. Everyone who sees your banners can become an active user of the app with nothing but two taps on the screen.
6. Email marketing
If your company has an existing mailing list, use it to notify all your former and current customers of the app’s launch in an appealing, original way.
Work with the user base and regularly address it via email with an overview of new features in the app or accompanying products and services. Integrate your email marketing with your content strategy.
of mobile apps

Your app doesn’t necessarily need to be paid-for in order to generate revenue. There are many different monetization strategies that can create much more profit than just to cover your investments.
1. In-app ads
The most common monetization strategy after charging users money for the app is to introduce ads into the app. You can offer advertising space in your app to companies on a Cost Per Click (CPC), Cost Per Action (CPA) or Cost Per Thousand Impressions (CPM) basis. CPM is generally more favoured by users as it allows the ads to be less aggressive than with CPC and CPA.
There’s no need to actively sell your app to advertisers these days. All you need to do is to partner with one of the large advertising networks such as InMobi, AdMob or Conversant.
2. Version without ads
A smart move is to offer users a paid-for ad-less version of the app alongside introducing the in-app ads. Users can make a one-time payment to get rid of the ads in your app for good.
3. Freemium
The freemium model entails a similar strategy. Yes, the app is available to everyone for free. However, the basic version only offers limited functionality. This basic version should ideally serve to spark interest in users and motivate them to purchase the full (premium) version with all the advanced features.
4. In-app purchases
Paid-for operations or various special items count for nearly half of the whole mobile app industry revenue.
As a mobile app owner, you can use your product to create a convenient purchasing platform that will enable users to add bonus features or special gaming items to the basket and make one-time payments.
5. Accompanying products and services
The app itself doesn’t need to generate the revenue. Many companies use their apps merely as a marketing tool to support their services or other products. Don’t forget to carefully design the app’s user journey so that it leads to conversions and sales.
6. Sponsorship
An alternative approach to ads, in-app purchases or the freemium model. You can try to find a strong partner whose area of business is strongly linked to the mission of your app and offer them the role of your app’s general sponsor.
7. Crowdfunding
Similarly to PC games, sneakers or watches, mobile games of all sorts also try their luck on crowdfunding platforms such as Kickstarter. If you want to stay away from ads and avoid charging people money for your app, raising funds from the users themselves might be a good approach.
8. Data licensing
Community-based apps such as Waze or Foursquare collect enormous amounts of data which they subsequently offer to their commercial partners for further use. The data licensing strategy makes these apps independent of in-app advertising, for instance.
What’s next?
Questions and answers

This is all we’ve got for you at the moment. The guide will definitely come in handy if you decide to develop your own app without having previous experience with mobile app development. Are you missing something specific in the guide? Do you have any follow-up questions? We aim to continually update and further develop the guide so make sure to let us know what you think in the comments, we’d be happy to have a conversation with you!