Including Voice coding will be great improvement
Since the keyboard in cell phone is very hard to use,especially in bus. It definitely will be an very useful to including voice coding which I mean you can develop a speech recognition tool that convert voice in to Linux command. Although iPhone itself can covert to natural language but the language list does not include Linux which is much more simpler language.
That brings up a lot of questions, as POSIX shell script is primarily intended to be written, not spoken. For example, is sudo pronounced soodoe or soodoo? When you say tee-put bell, do you want tput bel or tput bell? When you say ell-ess dash ayy, do you mean ls -a or ls -A? And unlike spoken language, if you misspeaks or the phone misunderstands you, you could destroy large amounts of data. And if you meant to spell things out, that would not only be slower but also much more error-prone, and you're better off just typing it, bringing a laptop in the bus, or just waiting it out till you get off.