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App development brief builder
Answer a few questions about your app to get a clear written brief, a rough complexity guide and a starting price. When you are ready, send the brief to Infinity from the same page.
Complexity guide
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A rough guide for scoping, not a quote. Apps start from £2,000, and the final price is confirmed after a short call.
Worked example.
A Sheffield personal trainer wants an app where clients can book sessions and track their workouts.
- Platforms
- iPhone and Android
- What the app does
- Clients book and pay for sessions, then log their workouts
- Features
- Accounts and log-in, payments for goods or bookings, push notifications
- Designs ready
- Not yet
- Launch
- In about four months
With 3 features ticked, the brief lands in the Moderate band (3 or 4 features), and the starting price shown is from £2,000 for an iPhone and Android app built from one codebase. The final price is quoted after a short call, and 'Send this brief' pre-fills the contact form with everything above.
How it works.
The maths and the rules behind the tool, so you can check it yourself.
Choose your platforms: iPhone, Android or both. Infinity builds both from one React Native and Expo codebase, so you do not need two separate apps. Then describe what the app does in one line, tick the features you need, say whether designs exist and when you want to launch.
The features to choose from are accounts and log-in, subscriptions or in-app purchases, camera or photo features, maps and location, chat or messaging, AI features, push notifications, an admin dashboard, payments for goods or bookings, and connecting to other systems. The tool counts how many you tick to give a rough complexity guide.
You get a clear written brief, the complexity guide and the starting price: apps from £2,000, with the final price quoted after a short call. The guide is for scoping, not a quote, because two apps with the same number of features can need very different amounts of work. 'Send this brief' pre-fills the contact form so you do not have to type it all again.
Tips.
Small changes that make the numbers more useful.
- Write the one-line description around who uses the app and the main thing they do, such as 'Clients book and pay for sessions'. If you cannot say it in one line, the first version may be trying to do too much.
- Split your features into must-haves and nice-to-haves. Launching with the must-haves and adding the rest once people are using the app is usually quicker and cheaper.
- Be clear about what people pay for. If you sell digital content or subscriptions inside the app, Apple and Google generally require their own in-app purchase systems and take a commission, while payments for physical goods or real-world bookings can usually use a normal payment provider.
- If you have anything visual, such as sketches, brand colours or screenshots of apps you like, mention it in the brief and share it on the call. It makes the app much easier to scope.
- Leave room in your launch date for testing and app store review. Apple and Google both review apps before they go live, and a first submission can need changes.
Questions, answered.
What should an app development brief include?
A good brief covers what the app does and who it is for, which platforms you need, the key features, whether designs exist and when you want to launch. Any systems the app needs to connect to are worth listing too. This tool walks you through each of those and writes it up for you.
How much does it cost to build an app?
It depends mostly on the features, the design work and any systems the app connects to. At Infinity, apps for iOS and Android start from £2,000, and the final price is confirmed after a short call. The complexity guide gives you a rough idea of where your app sits before that conversation.
Do I need separate apps for iPhone and Android?
Not necessarily. Cross-platform tools such as React Native and Expo let one codebase run on both iPhone and Android, which is how Infinity builds apps. Each version still has its own App Store or Google Play listing and goes through that store's review.
How long does it take to build an app?
It depends on the scope. An app with a couple of simple features is far quicker to build than one with payments, chat and an admin dashboard. You also need to allow time for testing and app store review, and the most realistic timeline comes once the scope is agreed.
Do I need designs before I get an app built?
No. Plenty of apps start from a written brief like the one this tool creates. If you do have sketches, brand colours or examples of apps you like, share them, as they make it easier to agree the scope and the price.
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