Well, I have come codes I:3

explorer - 100 gems

AJBDAY4 - 4th Birthday Cake
drawing - 500 gems
shadows - 500 gems
tigris - 500 gems
chimbu - 500 gems
adventure - 500 gems
spooky - 500 gems
ngk2015 - 1,000 gems 
twelve - 1 diamond
winter - 500 gems
pets – 500 gems
friendship - 500 gems ( I recently discovered twelve and spooky do not work :C )