Roku is recognized as the set-top box with the most online video content but until yesterday most of its devices were missing one of the world’s biggest video providers, YouTube, which was available only on the Roku 3 and Roku streaming stick. Now the firehose of video is available as an app on all of what Roku calls its “current generation” boxes — those made after July, 2011. With the addition of YouTube on all its devices, Roku catches up to the New Amazon Fire TV.