Regarding the official facebook pluging.
If i remember correctly it wont work on mobiles, however theres a paid plugin here on the forums that works great on mobiles. And its cheap too
Color mask would need webgl effects, i think. I remember having some deficulties with that on CocoonJS exporter for mobile, but you could also make image frames, and edit the pictures in a picture editing program, and then just change the frames to the color you would like.
You can store saved data with Webstorage (works great on mobiles)
I hope that helped a bit.