Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
Code Review by Codementor - Get an expert to review your code on-demand
JavaScript Operator Lookup - A full list of JavaScript operators with examples
Codebeat for iOS - Automated code review for iOS
DeepSource - Automated code reviews with static analysis.
CodeStream - CodeStream helps development teams resolve issues faster, and improve code quality by streamlining code reviews inside your IDE