Developed by the MIT Media Lab’s Center for Mobile Learning, the App Inventor lets you develop applications for Android phones using a web browser and either a connected phone or an emulator. All you need to get started with MIT App Inventor is a Google account to log in. The App Inventor servers store your work and help you keep track of your projects. You build apps by working with the App Inventor Designer, which lets you select the components for your app, and the App Inventor Blocks Editor, which lets you assemble program blocks that specify how the components should behave. You assemble programs visually, fitting pieces together like pieces of a puzzle. Your app appears on the phone step by step, as you add pieces to it, so you can test your work as you build. When you’re done creating your app, you can package it and produce a standalone application t o install. If you don’t have an Android phone, you can build your apps using the Android emulator, software that runs on your computer and behaves just like the phone. The App Inventor development environment is supported for Mac OS X, GNU/Linux and Windows operating systems, and several popular Android phone models. Applications created with App Inventor can be installed on any Android phone.