There are a lot of image croppers out there but very few allow anything other than rectangle or circle, let alone have it interact with your game. This Android plugin allows you to crop out a face from an image using 1 of 5 face templates and apply that image to any Texture2D GameObject.
If you want to apply this texture onto a character please ensure the character has a material id that this could attach too. See the character model in the demo for an example.
Android SDK: 19-25
Should integrate well with other plugins however refer to the Readme.txt and comments in the c# classes for more direction.
Any questions please contact me at phatboi.studios@yahoo.com