Free rice

http://freerice.com/#/english-vocabulary/1922 English word game which also helps to donate rice to the United Nations World Food Program.

Wordament

http://wordament.com/ Wordament is a free game for smart phones, tablets or PCs. Wordement is a puzzle game where you have to discover words from the letters on a grid. This game is great, very addictive!

Cambrige online Academy Island

http://www.cambridgeesol.org/exam-preparation/academy-island-game.html Academy Island is a game using different situations in English to progress to higher difficulty levels. The game is designed to help learners improve their English in a fun way.