Write and run Processing(.js) scripts on your phone or tablet. With syntax highlighting, examples and inline help.
Write interactive Apps in just a few lines of code.
You can even create 3d sketches (note you have to run these in Firefox as this is not supported by the components used by the built-in viewer).
See also Generate: Generative Art Tool which uses a language called Context Free to recursively generate graphics.
Support for Android Lollipop
9Apps 4.9
