As of now here's your options
UpRev - Best thing since sliced bread
VK-Pro - Plug and Play module (VK-Pro 2 now available)
Unichip (good for those who like less HP).
TechnoSquare - One of the first available but not much feedback
Jet Performance - Same as above
Black box - Probably the 1st, very simple but limited in what it can do. Plus the guy bail out of town.
Ebay module - Cheap HP for $20 but will cost more in the long run.
Coming "soon" Bully Dog Power Pup