The Disney Movies Anywhere app is Disney's proprietary digital movie archiver/watcher, with codes included in Blu-ray combo packs and the ability to buy movies separately. They've long since had iTunes and Google Play linked into the app - if you bought a movie on one, you can watch it through the other. Today, they've announced they're now also linked into Amazon Video and Microsoft Movies & TV; if you buy a Disney film in one of those two apps, you can also watch it in Disney Movies Anywhere.
But it goes both ways, as well; if your accounts are connected, you can also watch your Disney digital collection in the Amazon Video app and the Microsoft Movies and TV service for Windows and Xbox. There's also a dedicated Disney Movies Anywhere app coming September 15, 2015 for Roku, Android TV, and the app is available today for Amazon Fire products and the Xbox 360.
The link notably carries over all of Disney's properties, including Pixar, Marvel Studios, and Star Wars movies, letting fans watch anything from Empire Strikes Back to Avengers: Age of Ultron (which sees an early digital release today) to Toy Story 3 or the upcoming home release of the live-action Cinderella on the device of their choice.
Fans who link a retail account to Disney Movies Anywhere for the first time will get a free digital copy of Monster's Inc. from Disney and Pixar.