Moonlight-N3DS
Moonlight is an open source client for Sunshine and NVIDIA GameStream for the New Nintendo 3DS, forked from Moonlight Embedded. Moonlight allows you to stream your full collection of games and applications from your PC to other devices to play them remotely.
Original 3DS Note
While this app is operable on the original 3DS, the hardware decoder must be disabled and the framerate will be significantly lower due to the slower CPU. It is not recommended to use this app on the original 3DS.