https://techcrunch.com/2019/01/14/youtube-just-changed-how-you-navigate-videos-in-its-mobile-app/

YouTube is updating its mobile app to make it easier to navigate through videos. The company announced it will this week roll out a new horizontal swiping gesture that lets you move forward and backward through the videos you’re watching. Swiping forward takes you to the next recommended video, while swiping back will take you to the last video you watched.

The video will also resume where you left off, in that case, says YouTube.