What an account really buys the vendor
An account gives the vendor an identity to attach your records to, a channel for marketing, and a lock that makes leaving harder. It gives you a password to lose and one more service holding your customer list.
It is genuinely necessary for a platform that hosts your data or moves your money. It is not necessary for an app that writes documents on your device.
The privacy position, stated plainly
QuoteLocal has no QuoteLocal account, no advertising SDK and no behavioural analytics SDK. Business records stay local by default.
Optional Pro sync writes to your own private Apple iCloud container, which Apple controls and you already own, rather than a vendor database. Backups are password-protected AES-256 files you hold yourself.
What Apple still handles
App Store purchases are processed by Apple through StoreKit, and the app receives only the transaction and entitlement state needed to unlock Pro. Eutopix Labs does not receive full payment-card details.
That is the only identity in the loop, and it is the Apple ID you already have rather than a new account created for this app.