I have found this site only today http://www.what2learn.com/ and I can’t wait to share it with you. It has lots of interactive exercises although most of the published games won’t be of any use to you as they deal with Maths, History and some other subjects.
But it has some games devoted to spelling and this is where you can do a lot of practice. I especially like the game  below these lines because it trains your ears too. If you feel it’s too easy for you , you can always click here and choose a harder level or play hangman or whatever you fancy.

This site also allows me to create my own interactive games and I’ve decided to try the hangman game first and see what it looks like….  awesome!!! Come on ..what are you waiting for??? Play the game  and guess the word before Grandma is abducted by aliens..  Target language : Sports. Level: Pre-intermediate