Sortd - Rated the #1 App for Gmail
Mia - Virtual assistant for meetings
KanbanMail - A Kanban board for your emails.
Email Studio for Gmail - Send personalized emails, schedule emails directly in Gmail
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.
Julie Desk - Virtual assistant using AI to schedule your meetings