After lots of helpful feedback from beta testers and Hacker News, my typing tutor app “Quick Brown Frog” is live and open for business!
Some of the things I changed in response to feedback include:
price reduction from $29.95 -> $9.95
support both Google Checkout and Paypal options for payment
stats reporting (WPM/Accuracy improvement over time)
report on frequently mis-typed keys after practice lessons
allow automatic single/double spacing after end of sentences (very frequently requested)
implemented crawlable Ajax links for SEO
plus many bug fixes for cross-browser compatibility
I consider this an MVP-level release, which means that it still needs lots of work and polish (in particular, the look-and-feel of the UI).
The important thing is to get it out there, and start getting feedback from actual customers. Absent that, I’d just be spinning my wheels.