The classic word extender, but where would we be without ING words when our brains aren't quite working at full capacity? Still, let's not get snobby, a properly executed ING word can really improve your game. If you've got a few spare Z's and I's then your opponent may soon be quaking and sobbing as you start jabbing your tiles down with a smug grin.
You can also find a list of all words that start with ING
and words with ING