Play the basketball in the air!

Control the ball and try to keep it in the air.

At the end of the way make a basket to finish the level.

Collect the coins to purchase a new basketball.

Make sure that third-party apps are allowed on your device: go to Menu->Settings->Security-> and check "Unknown Sources"

Tap the APK file. Allow the app any required permissions it asks for. Then, at the bottom of the installer window, click INSTALL.

You'll see a confirmation the app is installed. Now you'll see the app available in your list of installed apps.