They charged us in the neighborhood of $10,000 to program the app and submit it to the store.
That is to say people who checked "iPhone app" in the "how did you hear about us" section during signup. It was about 6-7 signups per month, and I believe it's still bringing in signups (I no longer work there).
Also, by $10K in signups, does that mean seven or so signups for a $1.5K course?