Please, its not working in Windows 8.1 pro, latest Firefox. If I gets one email on gmail its showing 100+ emails in my gmails and the number is still increasing. BTW, google blocked my Gmail for 24 hours because its reloading the gmail continuously. So, I've disabled the Addon for now....I'll use it again when it will get fixed...also, will replace the rating.
Actually, it was very good addon...appreciate the work.