hey! One of said creators here! We haven't figured out how to monetize / properly fund this yet. It's more so a problem we saw and attempted to solve. The cost right now is a couple hundred dollars month in server costs.
Please don't take my comment(s) as criticism: you're doing a good job. Even if you don't make any money doing this, it's a fun thing to do. In the worst case Twitter will (acqui)hire you.