LiquidFenrir has released an augmented reality game for the 3ds:

PaintAR

An attempt at an Augmented Reality homebrew game, similar to the console's built-in Face Raiders Uses parts of QRaken for the camera code


Hello! This game is inspired by Face Raiders and Pokémon Dream Radar!
In short, paint splashes appear around you and you move your 3ds around to find them, and fire water at them to clean them out.
Controls:

A to fire water

L and R to change water type: there are 2 types of water, default (leftmost, always does 1 damage), and colored. Colored water does more damage the closer it is to the color of the paint, but can also be far enough to do 0 damage!

Y allows you to steal the color of the paint, but discards your tank, so you can't shoot for a while! use it wisely

Every 10 "kills", a BOSS appears! bigger and with more health than the other paint splashes, you can lock on to it with X

As usual for homebrew, START to exit

Concerning moving, I tried making it like Face Raiders or Pokémon Dream Radar, but it's not really a success. It works, but you can use the dpad or the circle pad to move around easier.

Warning, it can be difficult to find paint splashes, but dont despair! try moving up 45 degrees and doing a full circle on the right. For that, there is information about the gyroscope, accelerometer, and your current angles displayed on the bottom screen to help (mostly debug values, but could be useful )

download https://github.com/LiquidFenrir/PaintAR

via https://www.nintendomax.com/viewtopic.php?f=132&t=16668