SpellingCity is one of the best and most popular sites around for students/teachers learning Vocabulary and Spelling. This is done through a nice educational portal that allows teachers to find or create word lists that they can then integrate into educational online games. Also, there is a very nice iOS app that allows to view lists and play games on the go.
I highly recommend checking out SpellingCity by clicking here!!
*SpellingCity is an advertiser of Technology Tidbits.