Gmail Notifr is a free and Open source RubyCocoa Gmail notifier for Mac OS X. Check your gmail inbox at an interval and make your life more productive. Both normal gmail account and google hosted domain account are supported. Features: Support multiple accounts! (new!) Support Google hosted account. Check mail at a specified interval. Growl & sound notifications. Small & fast. No background daemon processes installed as Google's official notifier. Open Source & free!
What's new in this version:
Mountain Lion 10.8 support. Basic Notification Center feature was also added.