Alfred - A supercharged version of Mac's spotlight feature, which makes navigating only using your keyboard a breeze.
Bartender - Allows you to hide apps from your menu bar and minimize distractions.
Be Focused Pro - An extremely customizable Pomodoro timer.
Focus - Allows you to focus for a set amount of time and minimizes distractions by blocking out popular websites.
Drafts - A quick way to keep track of notes or lists. Great integration with the AppleWatch and iPhone.
LastPass - An application for keeping track of those long and complicated passwords.
Magnet - Organize all the different windows you are working with by snapping them into place.
Notion - This application pretty much does it all. Take notes, create outlines and databases and keep track of things.
Papers - A citation manager that exceeds expectations and allows to download directly from Google Scholar.
Things 3 - A supercharged version of the iOS' Reminder application.
Ulysses - A simple markup tool that allows you to write and minimize distractions.