The developer of papermill, the first Instapaper app for Android has written an analysis of his first week on the android market. The app is priced at 3.99€ and it requires an Instapaper subscription to work.
It has been installed on 411 devices.
approximately $590 in profit thus far.
After a week, the launch week.
Update (October 9, 2014): Papermill has been removed from the store so I’ve taken the link down since it’s a 404 now.