In Camera Awesome's settings (iOS version), I see an option to "Export to Camera Roll", but it leaves a copy in CA's library too. Is there a way to make the app use only the camera roll on the phone? Camera roll is what gets synced with the host machine, cloud, etc. I don't really want another copy to deal with.
No, that's not possible as to work with a photo, it needs to be in the app's own documents. At this point you could only manually remove the photo within Camera Awesome.
Keep in mind that in Camera Awesome the original of the photo is kept and even if you apply a filter, crop it or make any other changes, you can always go back to the original to make other changes. So the photo in the app and the one exported to the camera roll are not necessarily the same, if you make use of filters while taking a photo.