Does this currently have the functionality to add "clip art" type elements to a photo, where we can supply the clip art elements in the app (as a silly example, adding cartoon cat ears on a photo of a person)? If not, is that something you'd consider adding? Thanks for any insight/info!
I am not sure if I understand your question. The UltraCam download includes all the code and everything you need to get started to build your Instacam like application. The code is well documented so you can add additional filters etc.
Currently, the UltraCam only post on Twitter. I am waiting for iOS 6 to come out and then I will update the code to include Facebook functionality. I believe if you buy now you will automatically get the code when it is updated.
Are you running on the device or the simulator. Make sure that you have entered the Facebook username and password in the iPhone settings. This applies for both your actual device and also running the app in the simulator.