Gmail Manager
Gmail Manager 0.5.3 for Windows
Todd Long Browser & Email / Browser Tweak
Gmail Manager is a Firefox extension that allows you to manage multiple gmail accounts and receive new mail notifications.

Software Summary:

You can run Gmail Manager on Windows operating systems. Gmail Manager is a software product developed by Todd Long and it is listed in the Browser & Email category under Browser Tweak. Gmail Manager is a free software product and it is fully functional for an unlimited time although there may be other versions of this software product.

Alternatives in Browser & Email on Windows