I got this from a guy thats to build a mobile application what does most of it mean purpose (what problem does your application solve)

Audience (who will use your app? what are some examples of user cases?)

platforms (iOS, Android, web/responsive web, etc)

detailed feature requirements (consider both front and back end, if you can)

what services you need from Sourcebits (design & engineering?)

any important technical details (existing dependencies such as a server that your app will need to interface with, custom APIs, etc etc

any wireframes or other visual assets?

any existing apps with similar purpose / design / interactive sense

budget/funding limitations

development timeframe