Keep an eye on up to 3 profiles. The day one of them is marked inactive on haunt.gg, the bot sends you a message on Discord. Free, and outside the tiers. The same list is the one /watch shows in Discord: add it here, remove it there, it makes no difference.

Each profile is read once a day, in its own hour of the day, so the haunt API is never hit in a burst. A profile watched by several people is still read only once.