One thing that irritates us the most while searching YouTube is that you cannot sort search results to the most recent videos when you search for anything. Tube Junkies is a YouTube video manager on the iPhone. What Tube Junkies lets you do is, it shows the latest videos first as you see feeds in a RSS reader.
At times the apps also catches too recent videos (that actually arent converted and ready for the iPhone :(). The app also makes the video dim after you have watched them. If you use too much of YouTube on the iPhone, the App would be good enough for you. Though the pricing is steep at $5.99.