Sortd - Rated the #1 App for Gmail
Get My Receipts by cloudHQ - Organize your receipts in one click
KanbanMail - A Kanban board for your emails.
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.
gfeed - Turn your Gmail into a social feed to read through faster
Drag for Gmail - Transform Gmail into organized To Do lists (like Trello)