Developer Koushik Dutta, Koush for short, is well known around these parts for any number of apps. There's the ClockworkMod ROM Manager. There's AllCast. And if you want to back up specific apps and the data that goes with them, there's Helium (formerly known as Carbon).
Helium scratches a real itch for the platform. If you purchase a new device or wipe an old one, Google can re-install your previous apps, but it usually won't pull down your settings or game saves.