I’m confused, are you referring to a specific app that doesn’t have a back button or do you literally want the iPad itself to have a back button?
I literally want a back button on the iPad.
The YouTube app on iOS is a perfect example. Half the time the back button is not available, or at least not immediately obvious, so when I want to go back to the list of videos from a currently playing video, it’s either not possible or a pain in the ass. On Android all I have to do is hit the back button on the phone.
That’s the YouTube app’s fault for not understanding standard iOS conventions.