To create an app for android, you need to find a relevant idea that meets the requirements or solution to the problems. First of all, you have to study your potential market that who your rivals are and define your user profile. Because if you find your idea fabulous and create an app following that idea, you will have less chance of its failure. When there is no one to use your app, you will have lost a lot of time and maybe money. What is your opinion about this?