I'm not sure if this is an Android/phone/Firefox issue or a site issue, but this is the only site I have this problem with. Sometimes, when I open another tab and browse another site for a while, then switch back to the renshuu tab, I find that actions have been taken that I didn't do. Many times I've had a quiz open, and after switching to another tab and back, the question that was open has been answered correctly if a multiple choice, or answered as blank if fill in the blank. And just now, I had either an end of quiz or dashboard page open, and after looking at another tab, when I switched back to the renshuu tab a vocab schedule quiz was open.
