CodeStream - CodeStream helps development teams resolve issues faster, and improve code quality by streamlining code reviews inside your IDE
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
Refactor.io - Share your code instantly for refactoring and code review
JavaScript Operator Lookup - A full list of JavaScript operators with examples
DeepSource - Automated code reviews with static analysis.
codebeat - Automated code review for Swift