Your iPhone case probably isn't as awesome as Jake Potts'. Potts is a photographer who converted the glass back of an iPhone to a collodion process wet plate.
This means he successfully turned the glass of an iPhone into film and shot a picture onto it. The process of how it's done is interesting. The collodion wet plate process of taking pictures came out in the 1850's so this technique is super vintage.
So hands down, Potts has the coolest iPhone case because using such a centuries old technique makes it unique.