programming on handheld devices

Question

This is a little vague. But I've tried to put the things to the point.

As much as the handhelds (smartphones, tablets) are becoming extremely popular every passing day, What I wonder is, why there are no great programming tools for them?

With great processing power of these devices, I don't think there's any problem in running compilers or even small scale IDEs on them. It is perfectly acceptable that conventional programming languages are very difficult to write with an onscreen small keyboard. I'd never want to write java on my Android.

But are there any special tools or languages that are being developed in this direction?

For exaple, I had an android application for BrainF**k that worked fine with limited number of symbols (though the language itself is boring enough for not using it).

What in general is the scope of this area and direction of the research if any?

Thank You.

EDIT

Note that I mean programming ON mobile devices. Not FOR mobile devices.