there's this rumor....

i've heard people with an r4ds card, being able to play retro gameboy games on it and save. i've tried looking for that emulator but all i found was for pc. does it exist or is it just a rumor?

Gameboy, yes, Gameboy advanced, no.

Yes. The gameboy & gameboy colour emulator is called "lameboy". Whether it works on r4 I don't know, but it should (it works on my CycloDS). And also as Seph said, on just the r4 no Gameboy Advance emulation. If your looking for a gba emulator, then you need to get the expansion pack that goes in the gba slot.

u know where i can download a reliable 'lameboy'? thanks!

Here's the home site.