gameplaySP (gpSP for short) is a GBA emulator written completely from
scratch. It is still pretty young (only having started a 3 months prior
to the first release) and thus rather immature, but it does a decent
job of playing a number of games, and is being improved upon somewhat
regularly. It is currently somewhat minimalistic, in the sourcecode,
presentation, and features. Its number one focus is to deliver a GBA
gaming experience in the most playable way that PSP can manage, with
frills being secondary (although still a consideration, at least for
some of them).
This version of gpSP is optimized for the Raspberry Pi.