Note: After a closer look, it appears the site is free for a month or so after registration (longer if you have fewer students) and then you have to review games, perform other services for the site, or pay per student.
Legends of Learning is a new site that provides custom-built games organized by learning objectives. Teachers can create “playlists” they want their students to access and then monitor their progress.
They only have science-related games right now, but plan on adding more related to other subjects soon.
You can read more about it at USA Today’s article, ‘Spotify for learning games’ coming to classrooms, and I’ve embedded a video about the site at the bottom of this post.