Workona - A better way to work in the browser.

Sortd - Rated the #1 App for Gmail

OneTab - Whenever you find yourself with too many tabs, click the OneTab icon to convert all of your tabs into a list. When you need to access the tabs again, you can either restore them individually or all at once.

KanbanMail - A Kanban board for your emails.

One Tab Group - One Tab Group is a Chrome extension alternative to OneTab/Session Buddy, that allows you to manage your tabs & tab groups in one place. One click to aggregate all tabs & tab groups into one session.

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.