Unlimited Email Tracker - Track opens and clicks, set reminders and delays in Gmail
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.
Mailtrack.io - The best email tracking solution I've found. Free
Veloxy - A sales enablement app. Your calendar on steroids!
Email Tracker - Find out if your emails were read
Vipor CRM - Relationship management. Redesigned.