Rated 5 out of 5 stars

Whoah, this is really neat! .
Also, the bug mentioned in your about section is already fixed :)

This review is for a previous version of the add-on (0.1.3). 

> Also, the bug mentioned in your about section is already fixed :)
Oh, fortunately not: nsILoadContext.usePrivateBrowsing is still writable, and bug marked as RESOLVED FIXED. So it's fixed, but fixed using good way for us. :)
Anyway, I moved information about this warning into "Developer's Comments" section.