This one is the real deal for the Nexus 5.  Works perfectly and picture quality is amazing.  It should work perfectly for your device as long as you have slimport (Nexus 4/5/6, LG G2/G3, Nexus 7 2013, others) and use a good quality HDMI 1.4 cable.  To my knowledge, Samsung phones DO NOT support slimport.  If your phone supports slimport, you are much better off buying this adapter compared to MHL adapters which require power input.