Introduction

A URL scheme is a definition of how to handle and process particular kinds of URLs (or URIs) passed to it. The most common is http://, which we use every day, but there are also others, such as mailto:// and ftp://.

In native mobile apps, URL schemes can be used to allow one app to launch another app and pass data to it. This is incredibly useful if you want to share certain information between apps, such as a login token, or if you want to automate an app to do something such as posting a tweet for you.

Typically, a URL scheme will consist of a unique definition that, in most cases, reflects the name of the application. For example, on iOS and OS X, the tweetbot:// scheme will launch the Tweetbot client. Passing additional parameters to it will allow you to jump to a different view and even post a tweet.

A common way for developers to use URL schemes is by detecting whether a particular native app is installed and then launch it, instead of showing a web app. Google uses this...