https://www.theverge.com/2018/7/23/17604908/youtube-explore-tab-test-find-videos-channels

YouTube’s experimenting with a new Explore feature that will help users easily find new channels and videos on the platform while browsing on mobile. The Explore feature will pop up as a “tab” at the bottom of the app’s home screen for a select 1 percent of iOS users, according to Tom Leung, YouTube’s director of product management and host of the platform’s Creator Insider channel.

Explore will recommend videos based on what viewers are already watching, but with a “broader scope” than its home screen already does. “Explore is designed to help you be exposed to different kinds of topics, videos, or channels that you might not otherwise encounter,” Leung said, “but they’re still personalized — so they’re still based on your viewing activity.”