The HBO Go app is one of the most robust streaming video applications currently available on iOS, or any platform for that matter. The app offers over 600 hours of programming that can be streamed in regular or high definition. Originally launched in 2010, HBO Go is now available on iOS, Android, Roku, Xbox 360 and others.

When you first launch the app, you'll see a user interface that'll be pretty familiar to anyone who's used a video streaming app on iOS before. The home screen is populated with the latest episodes of popular TV shows and new movie releases.

At the bottom of the app are five buttons: Home, Categories, Search, Watchlist and Sign Out. The categories screen is split into the following: Movies, Series, Comedy, Sports, Documentaries and Late Night. You'll find that none of these are a throwaway.

Didn't know that HBO produced its own original documentaries? There's no shortage of them available on HBO Go - far more than you'll be able to find on HBO On Demand.

Movies can be added to the Watchlist either directly from the app or from a desktop browser. You can edit the Watchlist from your device too and indeed, there isn't a whole lot that HBO Go should do that it doesn't do and do well.

Arguably the best feature on HBO Go is AirPlay compatibility. It's also a point of differentiation as services like Showtime Anytime are still limited to an iPhone or iPad screen. With HBO Go on the other hand, as long as you have an Apple TV, you can stream any of your current directly to your 55-inch plasma.  

HBO Go is a free app, but you must be an HBO subscriber in order to use it.