The app definition statement is a concept that I’ve been obsessed with since I first read about it in the original iOS Human Interface Guidelines back in 2008.

An app definition statement is a concise, concrete declaration of an app’s main purpose and its intended audience.

It’s not exactly an elevator pitch, or a mission or vision statement, and it’s definitely not a spec. It’s just a definition. It’s what you would see if you looked your app up in the dictionary. It answers the questions “What?” and “For whom?”.

The process to create an app definition statement is pretty simple:

1. List all the features you think users might like
2. Determine who your users are
3. Filter the feature list through the audience definition

You end up with a single sentence which you can use as a litmus test for everything you do. Whenever someone on your team proposes a feature or a design, you should be able to run that through your ADS to see if what you’re doing makes sense. Will my audience want or need this? Does it belong?

Right now it seems like our industry is worried primarily about growth hacking, affiliate marketing, and App Store SEO. None of those things matter unless you make great software. Doing this simple exercise is the best way I’ve found to make sure that you make something people want without cluttering your idea or adding features for the sake of a checklist.

A few months ago, I asked some iOS developers on Branch for their app definition statements and got some great responses. Here are my favorites (coincidentally, some of my favorite apps):

• Grades: an app that shows students what they need to score on their next exam.
• Languages: lightning fast translation without an Internet connection.
• Paper: where ideas begin.
• Basil: a single place for your favorite recipes and makes it easier to cook them.
• Drafts: where text starts.
• QueueUp: Fast searching and adding for your Netflix Queue.

These don’t all follow the exact same template, but they do give you a quick one sentence way to understand the app. They let you see why the developers may have cut certain features and included others.

Writing an ADS is the first step in any new software project I’m thinking about. As soon as I have one I’m happy with, I put it in the project README and start designing.

Do you write App Definition Statements, or have you found an even better way to define your work?