Well, i made a small Turing machine for the nspire, complete with an editor for the transition functions.  It features:
 - editor (WIP)
 - saving, loading, importing and exporting transition functions in the editor
 - visualization of the Turing machine

Controls:
 - editor:
    - switch active element: [ tab]
    - insert transition function: [ i]
    - remove transition function [ r]
    - edit transition function [ Enter]
    The two upper Textboxes are for the input and the initial state
 - Turing machine:
    - calculation step: [ i]
    - reset: [ r]
    - run: [ g]

The user interface isn't final yet, so the controls will probably change.