Cardboard Enhanced Vision allows to see the images from the camera with some effects applied:

  • grayscale
  • black & white
  • sepia
  • negative
  • edge detection
  • chromatic
  • contrast+
  • dots
  • pixelate

Notes:

to change the effect pull the Cardboard magnet or click on the upper part of the screen. Than rotating to the left/right allow to select; some effects requires powerfull devices to work properly.

https://play.google.com/store/apps/details?id=es.blocknot.cardboardenhancedvision