- Need to jot a note: vim is far better than most native apps
- Need to access a remote system: use ssh or mosh
- Need a calculator: Python is there, with a lot of useful libraries
It even emulates a mouse, so elinks is quite usable on text heavy websites. For some mobile hostile websites it is more usable since the text is large enough to be legible.
A similar user friendly tool are the widgets, which makes it easy to launch a command from the launcher with a tap.
Given the number of development tools available, it is quite easy to write a program on the computer and run it on a mobile device.