Browser Sync
Keep multiple browsers & devices in sync when building websites. http://browsersync.io
Headstart
An automated front-end setup
Prettydiff
Compare code instead of text.
Csscritic
A lightweight framework for regression testing of Cascading Style Sheets
Sinon.js
Test spies, stubs and mocks for JavaScript.
Broccoli
Browser compilation library – a build tool for applications that run in the browser
Shipit
Universal automation and deployment tool written in JavaScript.
Ampersand
Quickest way to get started with ampersand.
Testcafe
A Node.js tool to automate end-to-end web testing.
Faker.js
generate massive amounts of fake data in Node.js and the browser