I wrote Mahjong words as a fun way to learn and use more words. I'm always looking to improve it, so if you have any ideas, please send me a message through my Suggest Improvement page. To play, click letters that are not dimmed until you have spelled a word, then click the 'Submit' button. If you want a full tutorial, I have a Video Tutorial that explains how to play beyond the basics.
I get a lot of requests to add more letters, and I may create a version that lets you do that in the future. Right now I have a dictionary that I am trying to keep small so I only go up to 8 letters. Also, I don't allow you to use proper nouns like Friday or England. A good rule of thumb to tell if you're using a proper noun is if it's usually capitalized.
You can also use the Suggest Improvement page to send me a friendly note if you're interested in saying hi :-)