Rated 4 out of 5 stars

This is a good start. But the addon needs more work to be complete. I couldn't try the addon because I use TreeDB Portable.

A few ideas:
1. Support for TreeDB Portable. This can be done easily by requesting the user to select the TreeDB Notes folder on first run of the addon after installation.
2. Support for sending selected text to a new treedb note, or the last open treedb note, or the last to last open note, or let the addon get treedb to ask us what to do everytime.
3. One area where TreeDB notes(Free) is deficient compared to Keynote is that Keynote can automatically monitor the clipboard and paste copied items into a note. So, you have to only keep copying the stuff you want to keep; You do not need to open the Keynote window again and again to paste it.
4. Combine the above feature with the Autocopy extension!

This review is for a previous version of the add-on (1.0.1-signed.1-signed).