The YouTube app for iPhone is the new standalone app for browsing the site now that Apple no longer includes it as part of the iOS. The app is much improved over the old version with a well-thought-out interface and all the features you're used to from the Web site.
Just like the Web site, with the YouTube app you'll be able to upload and watch videos, keep up with your favorite channels, browse your subscriptions and playlists, and much more. The app launches with the standard YouTube home feed if you want to see what's hot right now, but if you touch the menu button in the upper left, you get a slide-out interface for viewing your personal video favorites and channels, settings, and a huge list of categories from YouTube that are excellent for new video discovery. Back on the main screen, you also have a magnifying glass icon for search, and the YouTube app will predict results, giving you several options to zero in on the video you're looking for. You can also choose to search using voice by tapping a microphone on the right side of the search box and speaking your search term that way.
When it comes to actually watching videos, the YouTube app offers more options than its predecessor along, with an elegant way to quickly switch from full-screen video to a smaller screen with comments, video suggestions, and more. Simply turn your iPhone horizontally to view in full-screen with thumbs-up and -down buttons and subtitle options only a touch away while the video continues to play. There's also a share button that lets you post the video to Google+, Twitter, or Facebook, and other options like sending via e-mail or Messages. When held vertically, you get a smaller viewing area, but you can also use tabs to browse related videos, sift through video comments, and subscribe to the channel if you so desire. All of the YouTube video-watching features are laid out with the iPhone touch screen in mind, and even after viewing only a few videos, it's easy to see it's a big improvement over the original.
My one big complaint is that the new YouTube app is not available on the iPad. Hopefully Google will make an iOS Universal app before iOS 6 drops, or iPad users will only be able to use the YouTube Web site in Safari.
Now that as of iOS 6 there's no longer a dedicated YouTube app on the iPhone home screen, the new standalone YouTube app is your best bet for viewing the popular social video site. As long as Google comes out with an iPad version soon, this will probably (and deservedly) be the go-to app for YouTube fans.