Spree Games is a site developed by Marc Prensky for the purpose of cataloging educational games that are available online. Spree Games currently lists 272 games. On the site you can search for educational games by grade level, age, and subject area. Spree Games provides a short overview of each game's purpose.
Applications for Education
Spree Games provides an option to register for an account that students can use to track which games they've played and their progress on those games. Or you can simply go directly to the site that hosts each of the games and play them there. That is what I did this evening when I discovered this President's Challenge Game and I think that's how much teachers will use Spree Games too. Spree Games makes it easy for teachers to quickly find some educational games for their students to play.