iphone 10 vs android x
The general gestures are fairly similar. Swipe up to switch apps. Swipe from the edge to go back. There's some others, but those are the ones I mostly use.
Edge swiping from the left to go back is a welcome addition to Android. I missed it immensely whenever I was using that phone. Major improvement on this front.
Unlike the iPhone, on Android a swipe from the right also goes back. Initially I had some concern this would be confusing, but it hasn't. At all. I apparently rarely use this feature on iPhone, less than I may have believed if you'd have asked prior. This is also quite convenient given the larger size of the Android phone's screen. I have trouble reaching across to make a one handed left edge swipe. So I use the right edge on the iPhone and left edge on Android. This all feels quite natural.
As for the matter of what happens when I go back on Android, I remain as irredeemably perplexed as before. Does it go to the previous page? The previous app? The home screen? Not that I ever had much hope, but while the back button was on screen, there was the possibility that it might give some visual indication of whether it was operating within the current app, or would do something else. That's no longer possible.
Another issue I find is that while the iPhone uses swipe navigation on many screens, in some contexts apps provides additional visual aids like a back button. Android apps seem less consistent here. I assume they figure the back button on the bottom is sufficient clue, even if it's unclear where it will go. A minor inconvenience.
Switching apps on the iPhone is a simple swipe across the bottom. Android requires a swipe up and over, and after months of practice, this remains very unreliable. Approximately half the time I fail to provide sufficient lateral movement to trigger the gesture, and return to the home screen instead. And curiously, once you're back at the home screen, the up and over gesture is disabled. Up and hold works as a reliable alternative, but I much prefer the single gesture for quick switches back and forth.
Minor differences aside, both interfaces work pretty well. My initial concerns that there'd be a kind of uncanny valley effect, with two systems close enough but not quite identical resulting in lots of confusion, turned out to be unwarranted. I'm not certain, but I believe the physical size of the device plays a part in this. They feel different in the hand, and in particular, reaching for the left or right edge feels natural depending on whether I can reach for it. But I'm not about to buy a tiny Android phone and plus sized iPhone to test this hypothesis by confusing myself.