My girlfriend and I have been playing through Pokemon Ruby and Sapphire since we we don't have 3DS' to get X and Y. We had the games for GBA but our GBA games aren't working so well anymore so I got a really awesome emulator for Android called MyBoy emulator. That app rocks because it allows us to link over bluetooth or wireless to battle. I don't feel too bad about it because we actually own and bought the physical versions of the game when we were younger. Anyway, she's way further in the game than I am and I somehow missed a gym (???) Apparently it's been a really long time since I've played cuz I have 3 badges and no idea where the heck to go get the 4th one in order to battle my dad.
[soapbox]If you're interested in the MyBoy app for battling or linking Android phones, know that you'll have to have one paid version of the app, but the other person can use the free version of the app and it doesn't spam you with ads or anything. You can also fast forward, quick save, and change button layouts pretty easily. I know I sound like a walking ad, but if you want to breathe some life into Ruby and Sapphire and you want to play and battle with your Android phone, MyBoy is the way to go.[/soapbox]