Sometimes I want to identify typefaces that I see in webpages. It is a tedious task to look in the HTML or CSS source code to find it. The quicker method is to use the WhatFont action extension.
WhatFont is a classic one trick pony. Just highlight some text, open action extensions and choose WhatFont. A pop-up opens telling you the font name, font family, style, weight, size and line height. That's all it does and it's great.
Best of all, it's free in the App Store.