MIT App Inventor

App Inventor, a cloud-based tool, lets you build apps for your Android
devices in your web browser. The easy to use blocks-based programming
environment and live app testing on your mobile device make it the
perfect platform for:

Novice programmers seeking to get started with Android Experienced
android programmers who want to do rapid prototyping Educators looking
for novel ways to engage students through project-based learning

The App Inventor website (http://appinventor.mit.edu) offers all the
support that you'll need as you learn how to build your own apps,
including:

- Setup Instructions: How to set up your phone for live testing (or,
if you don't have a phone, how to start the emulator).
- Development Environment Overview: Tour the Designer and the Blocks Editor
- Beginner Tutorials: The best way to get started programming in App Inventor.
- Sharing Apps: Package your apps and you can share them with
friends or upload them to Google Play
- Resources for Educators: App Inventor has become a powerful tool
for introducing programming, mobile app development and
computational thinking in the K-12 space as well as university
programs.

System Requirements:

Computer and operating system
- Macintosh (with Intel processor): Mac OS X 10.5 or higher
- Windows: Windows XP, Windows Vista, Windows 7, Windows 8
- GNU/Linux: Ubuntu 8 or higher, Debian 5 or higher

Browser
- Mozilla Firefox 3.6 or higher
- Apple Safari 5.0 or higher
- Google Chrome 4.0 or higher
- Microsoft Internet Explorer is not supported

Phone or Tablet
- Android Operating System 2.3 ("Gingerbread") or higher