Do we have any minning app, that we just install and it gives us bitcoins ?
In the backend it uses oue phone's resources and in return gives us bitcoins ?
There are apps that
pretend to be mining. Smartphones (and even computers) are too weak for Bitcoin mining. For proper Bitcoin mining you need
proper hardware.
Most of those apps will show banners, maybe even ask you enter captcha codes and at the end it'll give you peanuts. Doesn't worth the time.