1 Automated Static Analysis & Security

1. DeepSource — Automate code reviews with static analysis
2. Code Climate — Engineering intelligence platform to diagnose where work gets stuck
3. Codacy — Check code quality and track technical debt across 30+ languages
4. Veracode — Holistic, scalable application security risk management
5. Embold — Find, prioritize, and fix anti-patterns and vulnerabilities
6. Visual Expert — Explore, analyze, and document source code

2 Peer & Formal Code Review Platforms

1. Review Board — Code, image, and document review at scale
2. Crucible — Review code across SVN, Git, Mercurial, CVS, and Perforce
3. Phabricator — Discuss, plan, code, review, and test in one tool
4. Collaborator — Peer code and document review for remote teams
5. Gerrit Code Review — Patchset-based review for Git development
6. Reviewable — GitHub code reviews done right
7. RhodeCode — Unified tools for Mercurial, Git, and Subversion
8. Codestriker — Open-source web application for online code reviewing

3 Platform-Native & Visualization

1. GitHub Code Review — Lightweight review built into every pull request
2. CodeScene — Predictive analytics to find hidden risks and social patterns in code