The tips and tricks button shows the count of the unread tips.

This mod will show the count of the other connected players above the players button.

The mod can be configured to always show the count, or only once every time you connect to a server.
(actually: no, on_gui_opened does not fire when the players button gets clicked, so for now it will always show)

This will serve as a prototype to test the concept before making a suggestions to the developers to consider adding it.