https://answersrip.com/question/index?qid=20130426172359AAbWrjA
read my other answer there.
if you are too cheap to support the real devs for the emulators, and would rather support code stealers, then atleast get a better emulator then johns...
if you read my answer in above link, besides those, this one "may" be a legit emulator, but im not 100% sure. Since this is one that hasnt been "proven" to be stolen yet.
us myboy advanced https://play.google.com/store/apps/details?id=com.fastemulator.gbafree#?t=W251bGwsMSwxLDIxMiwiY29tLmZhc3RlbXVsYXRvci5nYmFmcmVlIl0.
it has no ads, so you are not supporting illegal ports for the emulators (as even free versions, them havign ads makes them money, so just by using a free emu that has ads supports stealing)
Its also a much better emu then johns lol
the free version doesnt allow save states, you can only use ingame saves (which you should NOT use save states as your primary save anyway so), you can only do 2x speed fast forwarding, and you can only use cheat codes that are 1 line. (johns emu has the same thing with the lite version, which is why the multi line code doesnt work)
you could just go pay $5 and get gba.emu and actually support real developers of emulation, and aso get the best emulator available by a HUGE margin. so :3