- You can use the Posting Key role (even though you don't need it either)
- Your app is not on Google Store but downloadable from Google Drive
- You can verify users by them sending you a code from their Steem accounts (which is the standard way of doing it) instead of logging in
Be careful everyone. You don't need any key to use gaming apps or advertisement apps like this one
This great gaming app on STEEM doesn't require any key
https://steemit.com/gaming/@princewahaj/introducing-super8ballclub-the-first-ever-multiplayer-based-pool-game-for-android-powered-by-steem-blockchain-using-playfab-and