Useful Gmail Plugins

Let's use this thread to discuss useful Gmail Plugins!
Boomerang for Gmail.
Schedule an email to be sent later. Easy email reminders. Boomerang for Gmail is a Firefox / Chrome plugin that lets you take control of when you send and receive email messages. Watch on what you can do!
Boomerang for Gmail.
Schedule an email to be sent later. Easy email reminders. Boomerang for Gmail is a Firefox / Chrome plugin that lets you take control of when you send and receive email messages. Watch on what you can do!