Wow, those mockups look really good! A couple of comments:
* What happens when you click "Stop Scanning"? It seems like if the camera is the main background, clicking Stop goes ... nowhere?
* The icons don't seem very intuitive to me, but they're certainly better than nothing.
* I'm concerned that displaying the data associated with results (e.g. 7/10, $1.32, etc) will be too slow, since it may need to do network communication, etc. Could that be relegated to the next screen?
* I like the interface for showing the plugin actions. Much better than buttons.