I posted this program on Reddit and received a huge amount of support and thanks for the work! Many people have already gone on to Master 60 words or so, which pleases me to see that some have found good use of the work.

In today's update, the number of words in the word bank will affect the amount of experience points necessary to add more words. That is to say it starts at 50 experience points at the initial 10 words (it used to be 100 experience points) and every 5 words adds another 30 experience required, so that at 30 words it takes 170 experience. If the words in the bank decreases, so will the amount of maximum experience required. 

I'm still tuning the numbers, but the intention is to make the beginning of the game get faster into the meat of things while making later progression not become an overwhelming hodgepodge of words. While playing my own game, I noticed that I was getting words just a bit too fast, so I wasn't able to practice the ones I was interested in. From my experience, I think 35 - 45 words is sort of the sweet spot of words to sit at, which I hope this update will do.