One thing I've noticed, if you're on a phone with force/3D touch, you have to hold much longer than usual on the left edge of the screen to do a hold action, because of the app switching feature
Thanks, in some of the apps I've noticed the click-area is very small or shifted, and sometimes clicking something doesn't work.
I definitely have much better experience with the Android version than the iOS version. The iOS version has somewhat poorer control where a sliding motion is used. The display wants to slide in that case rather than the game control being used.