We’ve been hearing about Steven Soderbergh’s mysterious “interactive” HBO series Mosaic for years now without really having a solid idea of what it is and how it might work. Now this week they have taken the tarp off this thing by launching an app for iPhone, iPad and Apple TV that apparently features all 7.5 hours of the show. It is presented as a branching narrative that can be controlled by the viewer and also offers additional supplemental material to explore further. The show will also be released more traditionally as a 6-episode limited series in January on HBO. With a cast that includes Sharon Stone, Garrett Hedlund, Frederick Weller, Beau Bridges and Paul Reubens, this may not be the first interactive TV show ever released but it is probably the highest-profile attempt to date. Check out a couple of trailers for Mosaic after the jump and let us know what you think.