Zen is the Yandex personal recommendation service. It selects news articles, blog posts, and other publications that you may find interesting. The selection is based on your browsing history and stated preferences. Recommendations start appearing in your browser once there's enough material to analyze and base selections on.
This service is also used in desktop version of Yandex.Browser.
Recommended articles show up on your screen as a vertical feed. The headline of the first recommendation appears at the bottom of your screen when you open a new tab. Drag the headline up to see the entire feed.