Roku is recognized as the set-top box with the most online video content (now about 1,500 channels). But until today most of its devices were missing one of the worlds biggest video providers, YouTube, which was available only on the Roku 3 and Roku streaming stick. Now the firehose of video — from best to worst — is available as an app on all of what Roku calls its current generation boxes —those made after July, 2011 (more details on that in a moment).