alt Hacker NewsI was referring to IOS, not MACOS
Androids do have universal back button at the bottom on the phone or the same swipe gesture if you want but iphones do not.
Sometimes swipe (the direction and position is a guessing game), sometimes and x (right or left ) and the behavior is inconsistent too (back or close)
There are some guidelines but more often than not seems like every app has it's own method and you need to get used to it
In iOS, task manager and closure can't be overridden. You swipe right to return to previous application. You can swipe left for a couple of seconds if you didn't intend to do that.
You swipe up and remove the application from the stack, all processes of the application is killed.
Background processing has strict limits, and you need permissions to run longer than that, and for some use cases, there are no recourse. OS swaps you out or freezes the app.
If you want an app to work in the background, don't kill it, period. Push notifications are handled by the OS and is not hindered by this.