I fear this little utility might be usable only for a discrete set of fans. Technically speaking it’s a text-based application, but … well, I’ll let you take a look and see what you think.
In principle, it’s rather simple: undistract-me simply takes note if a shell command takes longer than 10 seconds to execute. If it does, it waits until the program finishes, then throws up the alert message you see in the screenshot above. Kind of cool, in an odd way.
Strictly speaking though, you’ll need all the underpinnings of a graphical desktop, plus whatever alert system is in use there, before you’ll get close to that kind of behavior. On my semi-graphical Arch system with just Openbox, I ended up adding gtk3, polkit, dconf, json-glib and a mess of themes and libraries before the git version was close to running.
So I don’t know if I’m being fair by including it. Don’t expect to suddenly plop this into place on your 400Mhz Celeron running screen, because you’re going to need a lot more to get close.
I won’t deny that I like the idea though, and if something comparable could be implemented in a text only environment, it might be worth trying. For my own part, I used to append long-running commands with aplay yoo-hoo.ogg so I would get an audible when something finished.
So in that way, I can sympathize. But unless you use a lot of terminal commands on a Linux Mint desktop and need some sort of blinky reminder when one finishes … well, like I said, it will probably only appeal to a slim range of fans. 
Inconsolation 