I'd be interested to hear how you marketed the app. Just building an app seems to be only half (or less) of the battle these days, as far as App Store success goes. I've got seven apps on the App Store, and combined they usually don't even bring in $200/mo. Discouraging.
I'll talk about that in one of the upcoming posts, but basically: I started with an app niche that I knew people were already searching for. And I knew that because there were crappy Spanish Bible apps already making money in the App Store. Since then I have started collecting users' email addresses which helps with promotions and new app launches, but initially all my traction was through search.
How did you know that? Just judging by the reviews or did you actually buy some to try them out?