Build an Android app for marking the exact positions on an image and a marker is displayed which is moved by directional pad (D-Pad)

I want to mark the exact position of an image via a marker moved by directional pad and onTouch (Both ways possible). And the coordinates of the touch position should be same in different phone sizes and when it is pinch and zoom. you can refer to the similar app for further information.(BOBT android app) - check the gaming part in that app.