You can get the three-button navigation bar back on Android by opening Settings and selecting 3-button Navigation under system display options.

Three-button navigation is getting upgraded in Android 16 with predictive back support. Here's what that means for you.

Android 16 Beta 1 has a predictive back animation for three-button navigation. Pressing and holding the back button will show a preview of the previous app or screen.

In fact, if you have a Shortcut for it, you can open any app just by tapping the back of your iPhone. All you need to do is set up the secret "button".