I was away from home without my laptop one night when I got an email from a friend I was collaborating on a project with. saying he needed some data crunching done that night if possible, because he needed to send the results out. I was able to download termux, git clone our project, run it, and write a ruby script to generate the figures he needed from the raw output, all within half an hour of somewhat painfully tapping my phone screen. would not even have been ten minutes had I had a bluetooth keyboard. I cannot think of how I would have done it at all without termux.