I just got a photojojo lanse for my nexus 5 and thought I should write a quick post saying that it NOT compatible with the nexus 5 despite what it says on the photojojo site:

The lens is the right size but the actual lens on the nexus 5 is controlled by magnets so with the photojojo lens in place the camera on the nexus cannot focus properly. Hopefully this might prevent others from ordering, in my opinion it is fairly deceitful for photojojo to advertise this product as compatible with the nexus 5.