Shutter (https://shutter-project.org/) but maybe it's time to poke around. Thanks for the survey.
@Don - thanks for the article. Gave this a whirl on Ubuntu 20.04 LTS. Works the charm w/a USB-Lighting but, I couldn't get the iPhone recognized using USBC-Lighting. Is this a known issue? (Checked libimobiledevice's StackOverflow... nada)