[Trent Adams]

Not really sure what you are after here, but Thomas has created a plugin called Online that keeps track of the posts since you were last logged in. That to my knowledge is the only plugin that keeps track of things since your last visit. You can find that at https://bbpress.org/plugins/

Other than that, maybe someone else can read this and give you some other feedback on where to start and where to start looking! Sorry I can’t be any further help without a little more info on what you are trying to do.

Trent