NBC just released an official (free) app for NBC Nightly News:
Stay on top of the day’s biggest news stories, anytime, anywhere. Join Brian Williams and the NBC Nightly News team seven days a week for top-notch political coverage, cutting-edge health reports, inspiring "Making a Difference" profiles and the most important stories at home and around the world.
-Easily scroll through and watch news videos
-Watch the latest NBC Nightly News reports
-Find stories in categories like Politics, Health, and Making a Difference
-Watch the most recent full broadcast in its entirety
-Share Nightly News videos on Facebook
-Read Brian Williams’s blog
Here’s the link.