You did not mention if your app is react, kotlin, android studio etc
Ans.
1, There are many things to consider before choosing a blockchain e.g blockchain popularity, transaction fees etc. You need to answer some questions before I can offer you with a better suggestion.
2, Yes.
Hello, thank you for responding.
Current backend is made on laravel/php. We have a two backend methods: top_up_user_deposit, withdraw_user_deposit that could be called by any of the payment provider services locally or via web.
And I would be glad to answer your questions!