Very good, but a tad glitchy – NicoPlayer - Niconico Video Player for free Review

Finally, a way to watch NND videos with an app on the US App Store! The video quality is very good, unlike what I've heard about the official NND app. The interface is in Japanese, but very easy to figure out even if you know no Japanese like me. My only complaint: A bit too many ads and a little prone to crashing after closing a video. For those saying it's impossible to use due to the ads: You need to flip your phone horizontally. Some of the ads' "x" don't show properly in portrait view. I've been able to log in and watch videos with no problems.
Review by NigelTheBlueGiant on NicoPlayer - Niconico Video Player for free.