1- Game Maker 8
This is my favourite. With Game Maker 8 you can develop educational games for your class as easy as drag and drop. This service also provides you with all the necessary tools to carry out your task from the ability to customize the background of your games to setting up iOS and Android apps for your games. Game Maker 8 provides a set of useful tutorials to help you start developing your games.
2- Kodu Game Lab
Kodu lets kids create games on the PC and XBox via a simple visual programming language. Kodu can be used to teach creativity, problem solving, storytelling, as well as programming. Anyone can use Kodu to make a game, young children as well as adults with no design or programming skills.