There's another project called TerminalIDE here:

https://market.android.com/details?id=com.spartacusrex.spart...

that also allows you to develop real android apps right on your device. TerminalIDE is primarily cli based and even comes with a version of vim already set up with a custom vimrc and relevant plugins. That said, I'm very excited about this project as Android is capable of being a "real" OS it just needs more real applications.