@duglor said in Apple 2 gs Emulators?:

Is GSPlus the only emulator right now that is capable of emulating the apple 2 gs?

No, there are several - see https://emulation.gametechwiki.com/index.php/Apple_IIGS_emulators.

If no, are there any lr-XXXX emulators for it? Does lr-Mess work with it???

Yes, upstream MAME is included in RetroPie and can emulate (among other systems) the Apple2GS. There's no out-of-the-box configuration for it, so you'll have to add your own system for Apple2GS and the emulator command for the system.