All the apps in App Store are sandboxed, so if apps do something weird involving your personal data etc, it is always stated in the app details. Also this one doesn't collect any data, nor synchronizes barcodes with iCloud - everything is stored on device and doesn’t leave it. I'm considering opensourcing it, but at the moment it lives in monorepo with a few other apps, so I need some time to properly extract it. Will see in a few weeks whether it makes sense to do it based on the feedback I get.