It's a fidget spinner. For your 3DS.
Tap on the bottom screen to rotate the spinner clockwise. No, it can't spin counter-clockwise. Don't ask.
Credits:
@TricksterGuy : for using several resources from your template, such as audio.wav, AppInfo, and template.rsf
@xerpi : for SF2D and SFIL, both of which were used to create this, as well as for your Makefile
@WinterMute, @fincs : for the 3DS application template, which was also used to create this