Pray For Paris is definitely the better known brand of the two, with the 'could be realistic but was actually photoshopped' Kanye photo which bubbled around the internet last year being the real ladder for the brand's popularity.
It seems that these hyper colourful prints have been taking over fashion recently - move over, neon, it's all about religious/lucid prints! As I'm a big fan I was looking into the origins of the designs and came across Leif Podhajsky's designs. They are, to put it simply, breathtaking. If you're a fan of music like Foals and Tame Impala you might recognise some of their album artwork from his pieces. It's funny to think that the designs all over the internet at the moment are so popular when the original designers of these types of patterns are so unknown!
PRVDNCE, Pray For Paris and Leif Podhajsky from the links here.