After searching "flip card" in google and our stackexchange site, there is no result and I have no ideas about how to flip a card by a corner. I am developing a ios card game with cocos2d, in this game, i just want to touch the right-bottom corner of back face, and hold on moving towards left-up direction. With moving a little distance, the card can flip to front face. Any ideas?
Your image example doesn't fit reality for the card you have shown. You are showing the wrong corner, but that's just me pointing out little things ;)
I will give you the simplified version for being able to flip an area that's a triangle.