Mobile phones are everywhere and almost every service in the world has its own application. If not, the website is responsive and can be used on a small screen with bad network, and not only on your desktop with a fiber network. As a tester of a website or an Android/iPhone/WinPhone application, you need to test it as a real user, meaning on one or more smartphones or at least on the most used by your users/customers. It includes manual and automatic testing though. What if you don’t have one billion €uros/$ollars/£ounds to buy all the smartphones needed to be tested? Will you rely on Chrome dev tools for browsers application, knowing that developers already “quickly” test their work with it?