Richard Byrne recently described two tools that could be of use to English language learners on his Free Technology for Teachers blog.
The first is a dictionary of American regional English. Read his description of it and access a link to the site at http://www.freetech4teachers.com/2013/12/the-dictionary-of-american-regional.html?#.UsBWbfZRaU4
The second is a game called Turn-O-Phrase, which practices colloquial phrases with images. Read about it and access it at http://www.freetech4teachers.com/2013/12/turn-o-phrase-helps-students-learn.html#.UsBWivZRaU4