watched
Togged, Letterboxd for television.
The definition
What everyone assumes: Watched is a checkbox. Corrected to: Watched is a logged record with a rating on it and a public profile behind it. Firebase identity, a signed session cookie, TheTVDB for show data, Postgres through Prisma.
Where it broke. A checkbox can't hold what you thought of it, and it can't show anyone else either. The box is the least interesting thing about having seen something.