Perchmount Fit Magnetic WOD Smart Phone Mount
This thing is pretty handy.  First of all I have an iPhone 5 as does my girlfriend so I wasn't able to test it out on other size phones but other reviews seem to indicate that it works on phones of varying sizes.  The magnet is really strong and keeps your phone secure and level even when gravity is working against it.  I have a metal rack behind my desk at work and stuck this sucker on the side and the magnetic grip was so strong that detaching the Perchmount from the rack knocked over stuff on my rack.  I