Rated 4 out of 5 stars

In your screenshot i noticed that you got your calendar in monthly view in right side column while viewing your inbox on same page. How did you do this ? Even i was looking for a way to make it look like this, similar to the outlook calendar layout.

This review is for a previous version of the add-on (2.0.4). 

This is probably the Today Pane you are referring to.
Click on the "Today Pane" button on the bottom of the window to open it.