Anyone can create iPhone and Android apps with global impact. MIT App Inventor is an intuitive, visual programming environment that allows everyone – even children – to build fully functional apps for Android and iOS devices. Those new to MIT App Inventor can have a simple first app up and running in less than 30 minutes. Our blocks-based tool also facilitates the creation of complex, high-impact apps in significantly less time than traditional programming environments. We will briefly discuss the platform and its design philosophy, build a simple app, and show how to build an extension for Android apps.