Your expenses, bills and savings goals live on the device. There is no account to create, no email address, no password, and no server of ours holding a copy — which is also why there is nothing of yours for us to lose.
One thing we will not leave out: the app does send anonymous usage analytics, and some of those events include amounts — the Privacy Policy lists exactly which and why. Merchant names, notes and account names are not sent, apart from a few names you type for bills, savings goals and income sources, which the Privacy Policy lists. No ads, and no advertising SDK.