SonarQube - SonarQube, a core component of the Sonar solution, is an open source, self-managed tool that systematically helps developers and organizations deliver Clean Code.

Flow State Training - Chrome extension with a timer to trigger productivity.

Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.

Copy.ai - We have created the world's most advanced artificial intelligence copywriter that enables you to create marketing copy in seconds!

CodeClimate - Code Climate provides automated code review for your apps, letting you fix quality and security issues before they hit production. We check every commit, branch and pull request for changes in quality and potential vulnerabilities.

Damn Good Tools - Easy-to-use, fun productivity tools—free (and open-source).