Folium is a multi-system emulator that covers Game Boy Advance, Nintendo DS and Nintendo 3DS.
Developed by Jarrod Norwell, Folium has been in development for a while, and requires some heafty hardware to run decently, according to some reports.
It's also worth noting that it's not free; you'll have to hand over $4.99 / £4.99 / AU$7.99 in order to download it. The good news is that money will go towards the app's development, and Norwell claims to have plenty of updates in the pipeline.
The Nintendo 3DS launched in 2011 and sold 75.94 million units worldwide. It was discontinued in 2020. Nintendo switched off the 3DS eShop and online servers in 2023.