This is a Joy-Con grip for the Nintendo Switch to use in tabletop mode. They provide an ergonomic all-around grip for your hands, fit in a travel case..., and are a decently quick print (~2 hours).
I've been playing a bunch of Breath of the Wild with it, and gyro aiming with the bow and arrow are even easier than in tablet mode.
Update February 12th, 2018: Uploaded with a split version of the model. Just print out 2 copies of the "flat fit half Switcherang.stl" model and they can be press fit or superglued together (usually cyanoacrylate works, but be sure to check your specific material). This eliminates the need for supports.
3d model print parameters
I'm still playing with settings (first successful print was with different PLA than what I currently have). So far 220C at 0.15mm layers and 0.9mm top... and bottom shells seem to be giving the best results for the speed.