Vein Camera is a smartphone/iPad vein finder app. It turns an ordinary smartphone camera into a vein-viewing device without the need for external equipment.
This app enhances the visualization of green and blue channels. Change filter settings to improve more green or more blue. By doing that it is possible to enhance the visualization of bluish and greenish veins in the body.
https://itunes.apple.com/us/app/vein-camera/id1222341362?mt=8