Tip Of My Tongue is an intriguing “dictionary-like” web application.
You can do a variety of things to identify a word or its spelling — actions that you couldn’t necessarily take with regular dictionary. For example, if you know the first letter and the last letter of a word, you would type them in and then the page will show the words (and their definitions) that fit those parameters.
I can certainly see how a tool like this would be useful to English Language Learners.
I’m placing the link under Dictionaries on my website.