Interview frequency: …
Short answer
On iOS, swiping from the left edge goes back and interactively reveals the previous screen. Modern Android allows swiping from either edge and uses Predictive Back to preview the destination before the user releases their finger.
Explanation
Predictive Back solves a common historical issue on Android: will going back close the app and return to the home screen, or return to the previous page? With the animated preview, the current screen shrinks to reveal what is behind it. If the user sees the phone's home screen and wants to stay in the app, they can cancel the swipe. Designers should avoid placing horizontal scrolling elements at screen edges where they conflict with the Back gesture.
Common mistakes
- Placing a horizontal image carousel exactly at the screen edge, causing image swipes to conflict with the system's Back gesture.
- Disabling the swipe-back gesture on iOS and forcing users to tap only the small Back arrow at the top.