Rated 5 out of 5 stars

This is a great little program that works well, is attractive, and is easy to use. I have one little annoyance with it. I wish it were easier to mark an item completed. There should be a check box you can check, or double click to mark complete, or something like that.

This review is for a previous version of the add-on (2.1.2.1-signed). 

You can always right-click on a reminder and select Complete from the context menu. But there are quicker ways to complete reminders. When a reminder is selected, pressing the space-bar acts as a quick-key to toggle an event complete. Alternatively, if you have the Complete column showing, you can simply click in the column to toggle a reminder as complete (a checkmark will appear in that column). To show the Complete column, click on the Column dropdown, which you can find at the right-most of the column headers (to the right of the "Description" header by default).
Hope that helps.
-Tom