What is the optimal or a good duration for mobile tap feedback?
Case: User taps a control/button and a comprehensive animation is used to tap show feedback. How long should it be?
Google has design guides about this issue and, without hinting about the animation duration, their examples seem quite fast to me.
Subsidiary question (and don't hit me, I'm not very good at UX design):
Would it make sense to have a faster animation for easing out than easing in for button feedback?
Say that my button would grow/shrink when tapped with a duration of 100ms would it make sense to have it shrink/grow back to its original size within 70-80ms instead?
The idea seems appealing to me but when I test it I find that it looks a bit weird.
If you wonder and if it makes any difference to you:
I am developing a mobile application that targets both Android and iOS using Xamarin.Forms (and NControl for animations)