If you specifically want to use the PPSSPP Emulator to play GTA on your phone, you can officially play the three titles actually released for the PSP: Grand Theft Auto: Liberty City Stories Grand Theft Auto: Vice City Stories Grand Theft Auto: Chinatown Wars 4. Safety Warning for ISO Downloads
You cannot run an unmodified PS2 game through a PSP emulator. The architectures are completely different. However, there is a legitimate way to play San Andreas on Android—and it’s better than any hacked ISO. gta san andreas psp iso top download for android