Suppose I have an image (say a jpeg or whatever format is nice) with exactly the same width and height (in terms of pixels) as the screen of my android phone (I have a Galaxy S7 edge running android 8.0.0).
Is there a method that allows to permanently overlay this image (with prescribed opacity) on top of my phone's screen, ideally without requiring root access? If the opacity part is difficult, one could build it directly into the image using a format that supports transparency, like png.
