When developing games for mobile devices you need to choose a platform (operating system). First of all, developers tend to create a mobile game for Android, and a little less often – for iOS. It would be more convenient to resort to a hybrid model, but with cross-platform development there will be additional costs.

The deciding factor here should be your target market. Focus on an OS that will be used by paying players. If additional costs do not scare you, it is better to count on support for both OSs right away.