Upcall - Upcall enables you to crowdsource your outbound calls. Collaborate with 1000+ on-demand callers worldwide for sales, marketing and customer support calls. Free trial.
Right Inbox - Schedule Emails in Gmail To Be Sent Later
Veloxy - A sales enablement app. Your calendar on steroids!
Recurrr - Send recurring emails
Streak for Mobile - The CRM for Gmail
FollowUpThen - The simplest way to schedule an email reminder