It is just a small script that shows the word count for the current textbox in the lower right corner of the screen. Useful if you don't have a clear sense of how much 120 words is, and you don't like to count words manually.

what if the backend software only takes in 120 characters and leaves everything else out?

Doubtful they would do something so opaque when their input is "Please try to answer each question in less than 120 words."

What if you just apply and not worry about things?