Finally an update on RIN, A Gameboy/ Gameboy Color emulator for the PSP, as it has been over a year since the last one has been released...
Davex's RIN mod adds two new features: Rewind and Mirror. The former is a nifty little Sands of Time-like feature that lets players warp back in time without using save states. By default, the rewind button is mapped to the PlayStation Portable's right trigger button, but according to davex, this can be changed in the Key Config menu.
The second feature, Mirror, horizontally inverts all game graphics. For example, if you're playing a platformer that's played from left to right, the Mirror feature will let you play it from right to left instead. Switching between normal and Mirror modes can be done through the Screen Size menu.
Davex's RIN mod is for version 1.21 of the RIN GB/GBC emulator. Please read the readme file included in the download before you install it.