Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
Source Insight - Source Insight is a programming editor & code browser with built-in live analysis for C/C++, C#, Java, and more; helping you understand large projects.
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.
CodeFactor.io - Automated Code Review for GitHub & BitBucket
SensioLabs Insight - PHP Project Quality Done Right.
Understand - Combines a powerful Code Editor together with an impressive array of static analysis tools that will change the way you work with code.