Email Architect - All-in-one system to write, manage and organize email
SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.
KanbanMail - A Kanban board for your emails.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
Sortd - Rated the #1 App for Gmail