codebeat - Automated code review for Swift
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
Stickler CI - Focus on your project, not formatting.
CodeStream - CodeStream helps development teams resolve issues faster, and improve code quality by streamlining code reviews inside your IDE
CodeFactor.io - Automated Code Review for GitHub & BitBucket
Code Review by Codementor - Get an expert to review your code on-demand