Megabox HD lets you stream and download HD movies and TV shows from your Android device.
You can choose whether to play the videos in it’s embedded player or to use a custom player or casting app.
Original app site: http://megaboxhdapp.com/
The original app featured annoying ads by StartApp but I think I disabled all of them and I removed the banner placeholder.
Hacks: ads removed
Credit: MegaBox HD (original release), ries (ad removal)