In the newest beta of the android app, when you enter a question then click the achievements button twice it will open two achievements views, one on top of the other. Continuing to press the button hides and shows the second view, and you need to click the x to make the first one go away. Interestingly enough this doesn't seem to occur inside the next question you enter by following a link.
Following a link in the achievements view does not close it either, and you can see it if you scroll down in the question you followed the link to. Then when you press back a couple times it closes the achievements view.