Tubex is an application available only for ios devices. This is a youtube app thats free with ad pops ups. The whole point of tubex is that its supposed to allow you to watch youtube videos more efficiently. So once you’ve download this app and login it will have an option bar for scrolling up and down for categories on the left. Once you click on a video you will have the option to adding to add to your playlist and you will also be able to change the quality of the video your watching. I will say that it does optimize the screen for youtube videos in a way you will be able to see more of the description box which is nice as more information on that video appears in the top fold.. The whole point of tubex is that its supposed to be a faster better way to watching youtube videos and overall it does an okay job. If your on youtube alot and who isn’t definitely check out tubex if your using an ios device.