I first covered View Source, an action extension to view source code in Safari, soon after the launch of iOS 8:
With iOS 8 extensions, apps like View Source can be possible thanks to direct integration with Safari and access to the DOM. Once enabled in the browser's share sheet, View Source will bring up a full-screen panel with source code you can read and copy. A share button lets you copy all text to the clipboard, send as email, or choose one from eight themes that include dark backgrounds and lighter styles. All these themes support syntax highlighting – a better visualization than my old scripts that didn't support highlighting at all.
If you're a web developer and work with iOS, View Source has turned into a must-have. It's $0.99 on the App Store.