I found free photo editing program that is down loadable for Windows users. This program allows you to remove that thumb from the corner of pictures or the random person standing the back of the picture.
It comes rated highly compared to Photoshop! It is one of the best editing programs that you can download for free. If you are in need of cropping out people or fingers over your lens, check this out.
Download it from here: http://www.pcworld.com/downloads/file/fid,72919/description.html