I was pretty fired up when I found this Better Terminal Emulator Pro.
A terminal emulator allows you to use Linux commands from command line using the bash shell
Seems that it was modified from the android store but does a pretty decent job.
Some comments:
Keyboard
A lot of standard keys are not available on the Fire, like the control key, pipe | , arrows, etc. There are some workarounds:
You tap once on the screen for the [Ctrl] key. The keyboard must be invoked for this to work.
"pipe" | is control-6