COOLMODO: Edmodo has opened its API to third-party developers who want to publish educational apps on its platform and tap its network of more than six million users (that's 600,000 teachers and the rest students). Over 35 companies have built services and products with the API, including Root-1, BrainNook, and Socrative. These are "premium" apps and Edmodo will get a cut of the licensing revenue from these products. (Revenue alert!) Edmodo CEO, Nic Borg, also snagged a prime speaking slot right after Arnie Duncan at SXSWedu to announce the move. Coming soon is a "Teacher-Developer Exchange,"which will aim to help teachers share their wishlists for new apps and programs with developers. Smart way to stay in synch with potential users.