Imagine sitting at your boring day job knowing that tens of thousands of dollars were pouring into your checking account during the day. That’s exactly what happened to Steve Demeter when his iPhone game Trism hit big in August.

The game, which he created in his spare time, made Demeter $250,000 in its first two months on Apple’s “App Store” — enough to entice him to quit his job as an ATM software designer and start his own game development studio.

But Demeter’s game earned mere pocket change compared with some of the other independent developers who’ve hit it big recently. Look no further than Ethan Nicholas, a one-man team who watched his own game, iShoot, climb to No. 1 on Apple’s…