AnDraw app for Android description
AnDraw shows an image full screen and switches off touch, so you can put a sheet of paper on the screen and trace the image without your palm scrolling, zooming or opening something else.
Adjust mode lets you place the image: pinch to zoom, drag to move, and buttons to rotate and mirror. Press Lock to enter tracing mode, where every touch is swallowed, the screen is kept awake, and brightness goes to maximum so the image shines through the paper.
Any volume key switches between the two modes, and the volume itself never changes.
AnDraw requests no permissions at all. Images are opened through the system file picker, which gives the app access to the single file you choose and nothing else.
