iOS is FULL of handy little things like that, but I'm not sure many of them are ever explained. You just have to stumble across it or read about it somewhere like reviews of the new versions of iOS.
Did you know in mail (and many other places) you can swipe table rows left or right for quick actions? Marco Arment recently changed Overcast to make features more visible because it seems many people, including power users, weren't even aware that gesture existed.
Now that I have an iPhone 7 re force-touch stuff can be very handy. But I forget it exists for weeks on end because I went so many years without it and it's totally hidden.