Free, no advertising, no marketplace. Your records are private unless you choose to share them, and they export freely — they are yours.
The full app also runs on the web, on any computer or phone: app.collectorscatalogues.com. The same account works in both places, and many collectors find a keyboard and a folder of photographs the fastest way to catalogue.
Coming after the Android launch. The app already builds and runs on iOS; it is a matter of when, not whether.