Rated 4 out of 5 stars
Small thing i noticed.Starting from Firefox 4 addons do not need to be extracted into install directory and 220.127.116.11 did not do this.
Yet 18.104.22.168 extracts itself.Is this by desing or just a small oversight?
Did not find the developers email.Otherwise i would have emailed him instead.The relevant mozilla page is here: https://developer.mozilla.org/en/Extensions/Updating_extensions_for_Firefox_4#XPI_unpacking
Because this add-on uses custom icons for all its dialogs and windows, leaving the add-on unpacked may cause serious performance problems, especially on slower machines. The Mozilla add-on validator displayed a warning about this fact, so now, by design, this add-on will be extracted.
You can find the developers email on the top right of the mozilla Form History Control add-on page where it says "E-mail your question".