Scratch - Scratch is the programming language & online community where young people create stories, games, & animations.
CodeStream - CodeStream helps development teams resolve issues faster, and improve code quality by streamlining code reviews inside your IDE
Cyberix3D - Free online 3D Game Maker. Make your own 3D games online!
codebeat - Automated code review for Swift
Open 3D Engine - Open 3D Engine is an open-source 3D game development engine in real-time.
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.