Bug-85 Remember last card position

@john-hu  I use static variable to store card position. Please help me review this one. Thank you~
Ok! I realize why you use static here. The static variable only keeps the state in app's life cycle. Once app is killed, this variable is gone and user goes back to the first item.

I can accept this kind of implementation for shorten. But we should file a issue to improve this to store in disk, like cache or preference.