The "2Do" application shows a blue dot in app's titlebar on macOS - what is it for?

What does the blue dot next to the other red/yellow/green dots do in the title bar of 2Do on macOS?

Solution 1:

The button is specific to the app "2Do" which you're running. It is not a general macOS "thing".

You are not the first person to ask why the meaning of the dot is, or what it does (if anything) when pressed. For example there's a Reddit thread about it here:

https://www.reddit.com/r/MacOS/comments/aw08z5/what_does_this_blue_button_next_to_the_traffic/

However even though the manual for 2Do shows a screenshots with this blue dot - it is not explained what the purpose of it is.

I would suggest contacting the support for 2Do to find out more!