I downloaded this app so I could learn hex better. It did the trick, but I found out how addictive flippy bit is. My annoyances are, not being able to flip two or more bits concurrently. I play it two handed, come on, let me type in both numbers at the same time. Second, the missiles take way too long to fire. The animation is annoyingly long and I keep watching myself get a game over even though I typed in the correct value.