Browser Sync
Keep multiple browsers & devices in sync when building websites. http://browsersync.io
Sinon.js
Test spies, stubs and mocks for JavaScript.
Should.js
BDD style assertions for node.js -- test framework agnostic
Broccoli
Browser compilation library – a build tool for applications that run in the browser
Testcafe
A Node.js tool to automate end-to-end web testing.
Shipit
Universal automation and deployment tool written in JavaScript.
Ampersand
Quickest way to get started with ampersand.
Gremlins.js
Monkey testing library for web apps and Node.js
Ag Grid
The best JavaScript Data Table for building Enterprise Applications. Supports React / Angular / Vue / Plain JavaScript.
Faker.js
generate massive amounts of fake data in Node.js and the browser