Messages - Is there a way to implement an "archive" feature? For those of us for whom text messages often represent an undone or unorganized task, it would be helpful to have an archive feature in Messages apps. That way, we could see which messages have not yet been responded to or dealt with. 

As it is, it's very easy to forget to respond.

Does anyone know of a solution?
No.

Neither is this functionality built into the Messages app, nor is it possible to enable it by any means.