LiveCode | Create apps for multiple platforms. Quickly. Easily. Free
LiveCode is a development environment for both stationary (Windows, Linux, MacOS X) and mobile (iOS, Android) applications modeled after the legendary Apple HyperCard. A visual editor allows fast design of user interfaces, a programming language inspired by the english language allows even non-professional programmers to develop professional applications and the concept of "modifying a running program" simplifies testing and troubleshooting.