What job do you do where you can be productive while interrupting yourself every 3 minutes to update a text file? Or am I misunderstanding something?

3 minutes is an arbitrary time limit, you can set it to anything. This forces you to act. Once you get to a flow state you can turn off the program.

Interesting. What I like about this is that if you're subconsciously procrastinating by avoiding doing the thing you need to do (by say, justifying something else less dreadful to do), this is immediate feedback that will snap you back to reality to focus on the one thing.