Shortwave Bookmarklet - Shortwave is an extensible quick-search and shortcut bookmark.
Sortd - Rated the #1 App for Gmail
Shortmarks - Shortmarks is like an enhanced speed dial for web browsing.
KanbanMail - A Kanban board for your emails.
Tampermonkey - Greasemonkey compatible script manager.
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.