http://graphwords.com/
https://www.wordnik.com/words/access
http://www.wordsmyth.net/
http://www.learnersdictionary.com/
http://www.bigiqkids.com/spellingwords/onlinedictionary.shtml
Here are some spelling games...
Alien Hangman
Spelling Shipl
Look, Cover, Write!
Spin and Spell
Construct a Word