I should mention i don't know the first thing about designing smartphones apps.
I hired a freelancer to create a mockup for a smartphone (Android/iPhone) app for me, and I was wondering if I'll be able to use some of the art he'll create in the final app, or are the apps using a different technology/format?
Edit (added): Should I ask him to work with a specific technology? (I'm guessing ps is the standard, but could it be that he'll work with another reasonable technology (i.e. not coal), and the mockup still will NOT be useful for the app?