Interactive art and installation

Quartz Composer seems to be the most popular for now; it’s part of Xcode for Apple systems. You need a developer account and be logged in for the following link to work:
Here’s a good guide to Compositing with Quartz Composer.

Processing is choice!
Max, a classic.

Simple App Builders
There are a lot these apps out there so here are ones that I’ve seen students use.

Phone Gap
Application Craft
Tasker app factory (Android only)