Rolling out this week on the YouTube iOS app (for 6S phones & above)!
From your video player:
Swipe left for the next video
Swipe right for your previously watched video
If you prefer, you can still tap for video player controls. More details here → https://goo.gl/SaRqyK pic.twitter.com/Es2ExHl8m9
There are several factors that determine the video quality on YouTube. Also, the quality is automatically adjusted based on your Internet speed. Here's more info: https://goo.gl/HTsKPR . Hope this helps.