gpSPhone is a port of a Gameboy Advance emulator by Exophase titled gpSP. Exophase wrote both gpSP and Temper from scratch. He is the most skilled emulator author I am lucky enough to know. When gpSP was released on the MIPS CPU based PSP, I was eager to port it to the ARM CPU based GP2X. With Exophase's permission I made the GP2X port and wrote a quick and dirty dynamic recompiler for it. Soon Exophase was introduced to the GP2X scene, rewrote my dynarec (yeah mine sucked in comparison!), and kept the port maintained.
When I took on the task to bring emulators to the (then) newly jailbroken iPhone and iPod Touch, my first choice was gpSP. I have maintained this port for around a year now. Exophase had moved on to projects such as Temper during that time. So by bringing gpSPhone to Cydia Store my intentions are to get more development done on gpSPhone. The move from a hobby to a product on Cydia Store motivates like nothing else can.
Exophase and I spoke before the release of gpSPhone, and we agreed to evenly split the profits. We also are in agreement that gpSPhone is a closed source project.
For those wondering what's new in v6.0.1 over v5.5.0:
* No advertisements.
* Slight increase in performance.
* Specifically written to support firmware 3.0+.
* Bug fixes related to stability.
* Removed linear screen filter.
Planned features for free updates:
* Firmware 2.x support. Due to popular request.
* Better cheat support. Save cheat settings.
* Better controller interfaces.
* Improvements to performance.
* Better audio support for the very fast iPhone 3gs.
* Perhaps if we can motivate Exophase, some improvements to the emulator that only someone of his skill can do. :)