As a developer you always want to test websites in different browsers. Initially I was using this Chrome extension to change the user agent. But while working on a Android app I needed to see response as sent from Android device. The extension only allowed Nexus 7 user agent for Android. Then I found that Chrome has added a new feature allowing us to change user agent from browser itself.
For this you need to open Developer Tools, go to setting, check override user agent and then you can select the user agent.