If you want a piece of software which makes Gmail better, you should know about:
- Free – Mail-Trail for Gmail: when you send an email, you set a number of days in which you wait for a response, and when that time passes, the email automatically gets sent to inbox, back again.
- Paid, but with better functions – RightInInbox.com – Schedule send emails in Gmail. Track emails. Set reminders for follow ups / Scheduled sending and email reminders | Boomerang for Gmail.
- Free – Rapportive – gives you detailed information about the people sending you emails.
- Free – Gmail Labs – Undo send – helps you cancel the sending of an email.
- Free – Gmail Labs – Canned Responses – helps you pre-write a message.
- Free- Gmail Offline – read & compose messages while offline.