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KnowFlow Ledger · Privacy Policy

Last updated: 2026-10-06 Effective: 2026-10-06

KnowFlow Ledger (formerly “Simple Ledger”, the “App”) is maintained by an independent developer and is a personal bookkeeping and finance tool. We take your privacy seriously. This policy explains what the App collects, how it is used, stored and shared, and your rights.

1. Information we handle

Data that stays on your device (the App’s core data; the developer cannot access it):

  • Financial records: amounts, categories, names, notes, dates, tags, attachment images and statement evidence that you enter, import or recognize.
  • Ledger and budget settings: accounts, categories, budgets, recurring items, installments, debts, term deposits, holdings, invoice ledger.
  • Preferences: currency, date format, appearance, notification settings, and your consent state for each AI feature.
  • Local AI data: your conversations with the AI advisor, conversation summaries and “long-term memory” (stored on this device; you can view, delete or turn them off in the advisor’s Memory panel), and a local cache of AI interpretations.
  • Apple ID identifier (only if you use Sign in with Apple): an anonymized identifier from Apple. We do not obtain or store your real name or email unless you choose to share it.

Data sent to the developer’s server (only when you use the relevant feature; see Section 3):

  • the text or summaries needed by the AI features you turn on;
  • a device identifier (a random number the App generates per device; it is not your Apple ID, phone number or advertising identifier);
  • Apple-signed transaction data for subscription verification.

The App does not collect your location, contacts, calendars, health data, browsing history or advertising identifier (IDFA), and does not use any data or device fingerprint to track you across apps or devices.

2. How we use information

  • Show and calculate your finances on your device;
  • Sync between your own Apple devices through iCloud;
  • Send local notifications you configure;
  • Process your requests and return results once you turn on and consent to an AI feature (Section 3);
  • Verify subscriptions, count free uses, prevent abuse and account for service cost (Sections 3.4 and 3.5).

We do not use your information for advertising, profiling or sale.

3. Storage and transmission

3.1 On-device storage and iCloud

All financial data is stored in a local SwiftData database. If you turn on iCloud sync, data syncs through a CloudKit private database within your own Apple ID; only you can access it and the developer cannot read it.

3.2 What is processed on the device by default

Text recognition for receipts and invoices runs entirely on the device with Apple Vision; images are not uploaded. Bill files and screenshots from WeChat Pay, Alipay and others, and bank PDF statements, are also read and recognized on the device by default.

3.3 AI help (optional, off by default)

AI help includes the AI advisor, one-sentence entry, merchant categories, column recognition, PDF statement parsing, reconcile suggestions, multi-row screenshot extraction, “Ask AI” interpretations (savings tips, anomaly log, reports, cash flow and so on), budget suggestions, bill rules, tag tidy-up and reimbursable-expense suggestions.

  • Every feature is off by default. Before first use, the App explains what is sent, what is not, and where it goes, and asks for your consent. You can turn each one off in Settings > AI Help at any time, after which nothing is sent.
  • What is sent: text from which phone numbers, card numbers and similar private details have already been hidden on your device, or summaries computed on your device (for example spending totals by category, amounts, dates, and names of up to 20 characters). Content that looks private is not sent.
  • What is not sent: images, statement files, full transaction lists, notes, accounts and balances.
  • Where it goes: through the developer’s own server (api.xingcihang.com) to a third-party AI model service, DeepSeek, which processes it and returns the result.
  • How the developer’s server handles it: it only relays the request and the result and does not store the content of your requests or of the AI’s answers.
  • The third-party provider: DeepSeek’s handling of what it receives is governed by its own privacy policy and terms. We do not give it your name, email, Apple ID or device identifier.
  • Your confirmation: any AI suggestion that would change your ledger (category changes, budgets, rules, tag merges, reimbursable marks) is shown first and applies only after you confirm; most can be undone.

3.4 What the developer’s server records

To enforce quotas, prevent abuse and account for cost, the server records call metadata: time, a hashed short identifier of the device’s random number, feature type, model, token counts, response time and success or failure. Server access logs include the request’s source IP address, time and path, used for rate limiting and troubleshooting. These records do not contain your request content or financial data and are used only for the purposes above.

3.5 Subscription (“AI Booster”)

Subscriptions are handled by Apple; the developer never sees your payment details. To tell whether you are subscribed, the App sends Apple-signed transaction data to the developer’s server to verify the signature. The server stores only a hash of the subscription’s original transaction ID, the device identifiers bound to it and the expiry date. It does not store your Apple ID, name or email. Each subscription can be bound to a limited number of devices.

3.6 Failure-sample feedback (optional, off by default)

If you separately turn on “Help improve recognition”, then when AI recognition does badly the App sends text with private details hidden to the developer to improve recognition; no images, and not linked to your identity. Samples are kept for up to 90 days.

3.7 Quotes, exchange rates and interest rates

Quotes, exchange rates and interest rates pass through the developer’s server, carrying only symbols and currency codes and no personal data.

3.8 Third-party SDKs

The App includes no third-party analytics, advertising or crash-reporting SDKs.

4. Sharing

We do not sell or rent your personal information and do not use it for advertising. We share it only:

  • with the third-party AI model service DeepSeek, as a provider processing your request, after you turn on AI help (Section 3.3);
  • where required by law.

5. Your rights

  • Export your data as CSV / JSON in Settings > Data Management;
  • Delete individual items or all local data in Settings > Data Management;
  • Delete your account in Settings > Delete Account, which removes the App’s local data (including AI conversations, summaries and memory, AI interpretation caches and AI consents) and triggers cleanup of the App’s data in your iCloud private database;
  • Withdraw consent for any AI feature in Settings > AI Help; view and delete memory in the advisor’s Memory panel;
  • Turn off iCloud sync in system Settings > Apple ID > iCloud; cancel the subscription in Settings > Apple ID > Subscriptions;
  • Contact the developer to exercise rights of access, correction, deletion, withdrawal of consent and portability (PIPL, GDPR, CCPA and similar laws). The developer’s server does not store your request content, and the metadata it keeps cannot be linked to your real identity; to have records tied to your device identifier deleted, tell us the identifier and contact us.

6. Children

The App is not directed at children under 13 and does not knowingly collect their information.

7. Security

  • Local data is protected by iOS / macOS data protection; iCloud sync uses Apple’s encrypted channels;
  • Communication with the developer’s server uses HTTPS;
  • The server does not store the content of AI requests or answers.

No method of electronic transmission or storage is perfectly secure; we recommend enabling a device passcode and Face ID / Touch ID.

8. Changes

We may update this policy. Material changes (types collected, purposes, third-party sharing) will be announced in the App or with an update.

9. Contact

For questions, complaints or to exercise your rights, use Settings > About > Contact Support in the App, or email support@simple-ledger.app.

The English translation is for reference; in case of ambiguity, the Simplified Chinese version prevails.