Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
Allows bidirectional access to Google Calendar
OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
Synchronizes contacts & groups between Thunderbird or SeaMonkey and Google Contacts. Imports Facebook friends, contacts you follow on Twitter, and more.
Scrolls the page smoothly when scrolling the mouse wheel (or keyboard arrows if enabled).
Switch the signature on/off or choose a new one from your predefined set...
Manage your tasks from Thunderbird, even while offline.