Right on time, Apple approved our 1.0.1 release today. If you've got 1.0, I strongly suggest updating. There are some major performance improvements, especially for large collections. Basically, because all of the content lives on our servers, the app has to decide what to ask for and when. We now have a better set of rules that distributes those calls out rather than putting them through all at once. Some users with 400 or more items in a collection were experiencing crashes; that should be over now.
Otherwise, we've been plugging away at getting the word out, building out more content, and generally trying to make Thumbprint a great place to be. If you've got any ideas on that front, we'd love to hear from you.