Great find! It says dimensions of 3.8" x 2.2" which probably absolute max. Use that as a guidance to see if it will fit your phone. For $0.95 shipped free, its not even a question if its a good deal
I have reviewed a number of grips (refer to my review link in signature), and most of them just give you a way to enhance the handling of the phone so it doesn't slip. This one has a bonus pocket for cc and some bills. If you get it, come back with your review comments. Just keep in mind that you still want to have a case on your phone for protection, enhanced grip is not 100% insurance from drop. So think about your favorite case and how it will fit in there.
I might even get it myself just for testing.