New and updated version of youtube mob app has really world class features like youtube itself. when I upgraded it I got a new feature by which we can download videos very fast because there is a special options by which we can choose required file extension that mean if we want to download low quality video which occupy fewer memory we can easily do. the concept of this app is splendid for youtube watchers.
Layout and design have not been changed much but look wise it is so for so good. we can access mostly features of youtube by this app including Upload video option. so I suggest you that if you are a youtuber or you want to watch news, tv, live shows etc. just go to play store and download it free.
one more thing I want to tell you that there is another useful app of google which is very useful to youtubers only i.e. Youtuve creater studio mobile app.