Web and mobile functional testing has never been so simple. All the tools that you need to create a solid maintainable apps are at your fingertips. Big and small companies are already using it to provide their users better experience. In this short talk I will tell you a bit about Appium and Selenium which are completely free open source projects that revolutionized mobile and web automation world. I'll show you why testing is important, when it is worth the effort and how to do effectively. Stay tuned if you are serious about the products you make - both free and paid ones!