Creating a Mobile App Specification Document

I hear from potential clients all the time, who have an idea for an app, yet they simply wish to get an estimate on how much it will cost “to make an app”. This is a very hard thing to just pull out of the hat, and usually starts to involve a conversation about the length of a piece of string.

What would really help people looking to gain further insight into potential costs, processes and timelines involved in app development is a Specification Document.

Completing such a document will help us gain a greater understanding of your requirements and potentially help you along the way. The next 10 pointers are a great basis for defining an app specification document:


Who are you? What is your background? Do you have any experience in tech or is this new ground for you? Why are you looking to make an app? Is it for your own company or do you need to sell the idea to company stakeholders? This all helps us gain a greater understanding as to your motives and the things you are looking to achieve.


Who is the app for? Why is an app the solution? What ages groups are you looking to target?  Is it to be aimed at Consumers or Business? By understanding your potential audience, you can effectively plan the design and functionality based upon their requirements.


Describe what you want the app to achieve, you know your potential audience - what is it you want to be able to accomplish with that audience? Drive traffic to the website? Push ticket sales or purchases? Enhance their experience whilst visiting your attraction?


Keep it simple and just explain the obvious. Not how it might do it, but what it needs to do - the work of how that is done is something that evolves through the design and development process. An example might be: The app allows users to book cinema tickets.


The mobile landscape is dominated by two different operating systems - iOS and Android.  iOS runs on all Apple devices and Android runs on most others such as Samsung, LG and Sony. Should your app run on both? Or just one to start?  Also, should the app run on both phones and tablets? Or just phones? This will depend on your Audience, Aims and Budget.


When it comes to creating an app, there are a lot of differences between these 2 operating systems.  They both have their own style guidelines on how an app should look and feel, and they both have different technical underpinnings.

To create a native app for iOS you must write code in Objective C or Swift.  For Android, you need to use Android StudioJava or Kotlin.  Because of the different code languages, it is often not possible to share code between the two operating systems, which means a lot of technical development has to happen twice.

There is an option to create a ‘hybrid’ app. This uses one programming language which runs on both iOS and Android, so in theory it saves time and money for development.  A native app is often written in HTML and Javascript, or a 3rd party tool such as Unity or Xamarin.  Native apps can suffer from being left behind the technological curve as they often don’t support the latest features of the operating system.  They can also feel less polished and are less slick than a natively written app.


Are you working to a fixed deadline? Are you looking for a phased implementation? Would a retainer model work better for you? Do you have set budget?

We need to know your expectations at the start in terms of when you need the app to be ready.


We don't need to know specifics of the functionality in terms of how the users will actually use the app - more a list of the things you need them to be able to do.

Explain that with a set of features listed and described, we can then look to provide a cost and time estimate.

For example an app that allows you to share your location with friends might involve the following functionality:

  • Take a photo, write some text
  • Log your location
  • Share with friends on the app and/or social media
  • View a feed of latest activity (both yours and friends or the community?)

This will then allow us to understand technical implementations that may be required, such as:

  • Social Logins / Manual
  • Notifications
  • Profiles
  • Connecting with Friends / Other app users
  • Location logging / Maps
  • Back-end Database integration
  • Content Management System (CMS)


As creators of award-winning app designs, the team revel in the ability to take an idea and turn it into a highly intuitive and beautiful design. Do you have an existing brand and accompanying brand guidelines? If so, we will use this when designing the mobile app to ensure it fits with your current corporate branding, website and products. If not, we can work with you to create a brand and associated style guidelines.


The app is finished, looks great and is highly functional and available for download!

This, however, is a continuing process and apps will need maintaining in order to stay fresh and relevant to the users. Standard maintenance issues include making sure that all functionality remains with each new update to the Operating Systems (OS) from either Apple or Google, whilst also exploring what new potentials these new updates create. Is your app making full use of the possibilities opened up by new hardware (such as fingerprint logins, 3D touch and more)?