This was an idea my brother had to help beat those ridiculously tricky GB games (Battletoads comes to mind!)
Its a simple cartridge style adaptor that goes between your console and the game. Hold Start+Down to save, Start+Up to restore. It's as simple as that!
Two variations exist, one with Non volatile memory - this means even with the power off, your save state will remain in the adaptor where you can resume your game, days, weeks, years later.
The SRAM variation will forget the save once you turn the GB off. This is most useful to get you through those hard levels but not a long term save solution.
There is also the option of a firmware update to enable up to 63 save states on the one adaptor, preserved in the inbuilt flash memory. This isn't included and may or may not be developed.
Taking pre-orders now. Estimated 3-4 weeks before all the parts are in, and the product due to ship out.
Suitable for use in GBA, SP, GBC, Pocket and DMG(with lockout tab removal)