Notico

Notico's own tagline is simply "convenient reminders in chats," and the detail worth calling out is "in chats" plural — it is built to set reminders inside group conversations, not only in a private chat with the bot, which fits a team or family group that wants a shared nudge rather than everyone setting their own separate reminder.

It maintains a public news channel and a separate support channel, both linked directly from its bio, which is a reasonably strong signal of an actively maintained project compared with a bot that has gone quiet. As with most bots in this category, treat the specifics of syntax and limits as something to confirm inside the bot itself via /help, since none of that is spelled out in the short public bio. Having a real place to report bugs and get answers is not a given for a small independent bot, so it is worth noting as a point in Notico's favor.