Build a local-first budgeting ledger with automatic encrypted backups, one-click local export, verified restore, and assisted migration from common budgeting-app exports and bank statement files. Household members can share a ledger through an optional encrypted folder they control, while bank connectivity remains optional rather than required. The initial product should prioritize data custody and recovery over forecasting or financial advice.

Recent reviews across numerous products show recurring sync failures, inaccessible historical data, broken cross-device transfers, unreliable bank feeds, and growing resistance to forced subscriptions. A portable ledger is practical to launch because its core value can be delivered through local storage and file imports before adding complex bank integrations.