What are some alternatives?
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.
SonarQube - SonarQube is code review and management software. The software is developed by SonarSource, which was founded in 2008 by Freddy Mallet, Simon Brandhof and Olivier Gaudin. Read more about SonarQube.
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
ReSharper - ReSharper is a productivity tool for visual studio that provides tools and features to help you manage your code.
Phabricator - Phacility - Phabricator
Review Board - Stress-free code review for teams of all sizes