Tools that help speed up responsive web development include HTML5 boilerplates to avoid duplicating code, frameworks like Bootstrap and Foundation that provide grid systems and styles, and tools for testing designs across screen sizes like browser plugins and emulators for simulating mobile devices. Common responsive design testing tools include browser plugins that allow resizing the viewport, online services that emulate different devices, and emulators for iOS, Android and other mobile platforms provided by their respective developers. Frameworks aid development through grid systems and prototyping, while testing tools help ensure responsive designs work well on varied screen sizes.