Code coverage for any Go package

Code review for GitHub repositories, free for public or personal repos

Code coverage tool (SaaS), free for Open Source and one free private repo

SEO tools but with also code verifications and different types of devices

Live interactive cross-browser testing, free only 3 minutes sessions with MS IE 9 under Vista at 1024 x 768 resolution

Advanced static analysis for automatically finding runtime errors in JavaScript code, free for Open Source

Continuous inspection platform, free for Open Source

Programming language aware diff for GitHub pull requests and commits, free for public repositories

Static code analysis for Java, C/C++, C# and JavaScript, free for Open Source

Code Quality for Go projects, free for Open Source

Gerrit code review for GitHub repositories for free

Comments on GitHub commits about code quality, free for Open Source