Face flag painting development

Is this an app to visualise how flags will look when painted on someone's face?
Assuming that's the case, then it's going to use 2D graphics at least, to draw things. You might want to have one screen which allows the user to design the flags, or provide templates to colour in. Then have a blank face, onto which you can project the flag designs.
Loads of links here to get you started with 2D graphics:

https://www.google.co.uk/search?q=android+2d+graphics+tutorial&oq=android+2d+graphics