Mac: Mobile devices have plenty of better ways to watch YouTube, allowing you to have a more immersive experience. Play+ brings easy browsing and simple full-screen viewing to your Mac desktop.
Play+ offers a familiar tablet-like interface that works well on the desktop too. At the bottom of the screen, you get shortcuts to popular YouTube categories, search, your favourites and your viewing history. Elsewhere, you can browse through popular videos, and you'll find a convenient comment thread on the right.
Play+ utilises YouTube's HTML5 player, so videos load quickly and your processor is unencumbered by Flash. The downside, however, is that if you have the now discontinued Quicktime Component Perian installed, you won't get sound with those videos. Perian messes with Quicktime and isn't compatible with the YouTube HTML5 player, so it therefore doesn't work with Play+.
While we'd like to see compatibility, Perian has been out of development for a while so you might want to start relying on something else. That aside, if you're looking for a nicer way to browse YouTube on your Mac, Play+ provides.
Play+ ($1.99) [Mac App Store]