I saw some interesting work on touch programming languages at Onward. You may already have seen Codify. That is still a mostly textual language, as the clickety-click of the keyboard in the video attests. The new research explores how to program entirely in touch, which requires avoiding typing as much as possible.
TouchDevelop is a project at Microsoft Research focused on programming phones. It is fairly conventional semantically. They take a hybrid approach to syntax, using text at the statement level, and structure editing above. Statement editing is facilitated by strong auto-completion guided by pick lists. They make the interesting observation that static typing is a requirement for touch programming so as to enable such auto-completion. YinYang, also from Microsoft Research, is aimed at tablets and explores an unconventional semantics of events particularly well suited to games and simulations.
One might scoff at the toy-like nature of these languages. But remember that most of the major innovations in computers have started as toys. In fact touch might be the only way to eventually liberate programming from text. Frankly, the only way to get most programmers to stop using text editors will be to take away their keyboards. On the other hand, I saw a bunch of people at SPLASH/Onward using iPads with keyboards.
Programming on the small screens of phones and tablets also forces you to drastically simplify the language, offering yet another virtue from necessity. I’m liking the way this is going…