"I did it"/"I must do it" check box

[Shogo]

Hi

First I'm sorry for my bad English (I'm French )

I want to know if that kind of mod exists :

A check box you can hit when you did something?
I explain what I mean. My members want to know wich action they did (in my board, each thread is an action). That would be cool if when they read the thread they can choose 2 options (2 buttons?) -> "I did it" and "I must do it later". And if they "did it" a text or image come near the title of the thread ==> only the user who clicked on "did it" can see "I did it".

I think this mod looks a little bit like "Installed"/"Uninstalled" in this board but impossible to find something like that.

Is this mod exists?

Thanks

Best regards