Followup.cc - FollowUp for email is a lightweight productivity suite that keeps your conversations and tasks from slipping through the cracks. Set perfectly timed reminders that arrive at the top of your inbox, right when you need them.

Out of Office Email Generator - Personalized, witty OOO replies for guilt-free vacationing.

Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.

Rebump - Automatic follow up emails. Keeps on bumping until you get a reply.

FollowUpThen - The simplest way to schedule an email reminder

Cop-Out - The ultimate excuse generator