Seems to be an abundance of so-called sticky notes for Mac but I haven't found one that will stick to a specific document or window and otherwise remain hidden, like Notezilla - a hugely valuable program that keeps me a prisoner of Windows (in addition to my MacBook Pro, not instead of). Seems like such an obviously desirable feature I am wondering why no one has done it for Mac - or have I missed something? Or is it the architecture of OSX that doesn't allow it?