Thunkable is a powerful drag-and-drop app builder made by two of the first MIT engineers on 
MIT App Inventor.
The platform is geared for the more professional user who may want higher quality, robust apps for their business, community or just themselves.
It has two main components:
Designer: Allows you to create an app UI by adding different UI components to your screen, such as buttons, TextBoxes, GoogleMaps, etc. It also allows you to add non-visible components to your apps, such as SMS receivers or NFC sensors. More Info »
Blocks: Thunkable has a blocks-based programming language similar to 
Scratch that makes it easy for novice programmers to use, but is sophisticated enough for seasoned developers to use (you can make functions, variables, callbacks, etc.).
FEATURES
Cloud-based Tool - You don't need to download large development suites, command-line kits, or simulators.
Templates - You can use the many built-in app templates as they are, or make changes.
Real-Time Testing - Make your changes online and see them on your device instantly with the Thunkable mobile app.
Ready to Ship - Upload your apps directly to the Play Store or send them to friends!
