It seems a strange specification to have - why that in particular? Are you thinking "democratising development"?

You can use MIT's AppInventor via the website, so presumably you could use an Android based web browser if you really wanted to. Seems like it would be pretty painful trying to do that from a small screen device however.

Why would you want to ? Can you develop Windows apps on a Windows RT device? What about iOS apps on an iPhone? Or Blackberry apps on a Blackberry? Despite the fact that you can with tools like AIDE on Android, the devices are meant to be low-powered convenience devices, not developer workstations. I think you might be misinterpreting their purpose?

I've found AIDE to be an interesting option for developing on the device itself.

Tasker?