SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.
Sortd - Rated the #1 App for Gmail
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
KanbanMail - A Kanban board for your emails.
Email Design System Playbook - Learn to design emails faster with a design system
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.