No timers yet. Pick a duration above.
Half an hour with a book and nothing else. The dial sits quietly at the edge of vision, giving up a ring every minute and a half, and the double chime at the end is the first sound it makes.
A set half hour puts a boundary around the book, which keeps the phone out of reach. Most people read further in one timed sitting than in scattered minutes.
Set any length you like on the timer. Thirty minutes is preloaded because it is long enough to sink into a chapter and short enough to fit before bed.
Add it as a browser source in OBS; the background stays transparent. Change t for any length.