Another cool one is an unofficial YouTube client app called ThirdTube which is pretty cool. There’s an emulator for the Virtual Boy called Red Viper which just had a huge update recently, which made every game in the entire consoles library run accurately at full speed (and even the 3D from the original Virtual Boy works too!). You can add custom themes to your main menu with the app Anemone3DS and can make a backup of the save data for each of your games onto your SD card with an app called Checkpoint. They’re all my favourite; otherwise I haven’t explored a large amount of what is on offer still.