Fiddler - Fiddler is a debugging program for websites.
Fluxguard - Deployment, Defacement, & Security Monitoring
Inspect Element - Inspect Element is a multi-functional tool that is introduced to get information about what makes the web tick, figure out what is broken in your sites, and mock-up what a specific color or font change would look like.
Firefox Page Inspector - Firefox Page Inspector is a multi-featured tool that allows you to navigate through the components that go into rendering their pages, enabling you to achieve better performance, find bugs and check mobile views, and many others.
Typescript - TypeScript allows developers to compile a superset of JavaScript to plain JavaScript on any browser, host, or operating system.
Sken.io - The most advanced tools for tracking changes on websites.