As the title has already stated, it is free for a limited time so if you are a Watchman fanboy you will need to get it ASAP! Just go to TV Shows and look through the coverflow at the top. The teaser trailer by the way for the movie is amazing!
This reminds me of the old Marvel animation on tv! It had Captain America, Incredible Hulk, Namor, Iron Man, and Thor. Very cool!