Review for Notebird by Old-School
Rated 3 out of 5 stars
Pretty good so far. This is a simple way of adding notes to single emails, and the toolbar icon changing color for messages with notes is cool. However, it gets three stars because you cannot add a note to a thread, only to a single message at a time.
Adding a note to a thread so that the note shows for all messages in the thread is a must.
To create your own collections, you must have a Mozilla Add-ons account.