1. Introduction
This policy explains how PX Apps (“we”) handles information when you use the Sổ Tiền Hôm Nay (Today’s Money) app and its landing page. The app is designed offline-first: we minimise data collection and keep your money book under your control, on your device.
2. Scope
This policy covers the app on iOS and Android, the official landing page, and support requests sent directly to us. Apple’s, Google’s and third-party services are governed by their own policies. Section 5 applies to app versions that include the usage-data and crash-report feature, on both platforms.
3. Data you create in the app
Depending on how you use it, you may enter amounts, transaction types, dates, notes, categories, debtor or payee names, debt status and display settings. This may be your personal or private financial data. It is processed locally to:
- Store and display your income, expense and debt records.
- Calculate totals and build reports for a period.
- Let you search, edit, delete and manage transactions.
- Remember categories, the trade template and settings on the device.
4. What we do not collect from your money book
- No account or sign-in is required.
- Your income, expense and debt entries are never sent to our servers.
- We do not sell or rent personal data.
- We do not use money-book contents for advertising or user profiling.
- We do not access bank accounts and do not move money.
5. Usage data and crash reports (optional — OFF by default)
Sổ Tiền Hôm Nay is offline-first. Everything in your money book — income and expense amounts, names, notes, categories, debts — is stored and encrypted on your device. We do not operate a server that receives your money-book contents.
Two separate choices, both OFF by default. The app sends a minimal amount of technical data only when you agree:
- Send usage data to improve the app — OFF by default; turn on/off anytime in Settings.
- Send technical crash reports — OFF by default; turn on/off anytime in Settings.
The two choices are fully independent. If you do not agree, the app remains fully usable — no feature is locked. Your choice is stored on the device itself: no account, no server, no cloud sync.
5.1. If you enable “usage data”, we may receive
- The type of action in the app, as technical event names (e.g. “first record created”, “report screen viewed”).
- The record type (income / expense / receivable / payable) — a classification only, never the content.
- The standardized template code in use (never a name you typed).
- App version, platform, technical sequence and timing.
- Collected automatically by Google’s services: a random installation identifier (app-instance / installation identifier); on iOS also the identifier for vendor (not an advertising identifier); device information (model, brand, OS version, language); session and engagement data; an approximate region inferred by Google from the IP address; and information about Premium purchases.
About Premium purchase information: when you buy Premium, Google Analytics may automatically record the product ID, product name, price, currency and quantity of the Premium package. This is about the app’s Premium package — never any amount or content in your money book.
5.2. If you enable “crash reports”, we may receive
Technical error information: stack traces in the app’s code, normalized error codes, app and OS version, device type, a technical installation identifier, and technical state related to the error.
5.3. We do NOT receive your money-book contents
PX Apps does not send to Firebase Analytics/Crashlytics: income or expense amounts · debt values · transaction values · people’s names · customer names · debtor or creditor names · notes · book contents · backups · exported files · phone numbers · emails you enter in the book · contacts · precise location · advertising identifiers (Advertising ID / IDFA).
The app also never sends receipts, purchase tokens or order IDs to Firebase, and does not store them on PX Apps’ servers.
5.4. Purposes, and what we do NOT do
Purposes: product analytics to improve the app; troubleshooting when you enable crash reports; measuring the effectiveness of campaigns that introduce the app (attribution and campaign measurement) through a link with Google Ads.
- No personalised advertising.
- No remarketing audiences.
- No audience sharing.
- No advertising identifiers (Advertising ID / IDFA): the Android release removed the permission entirely; the iOS build uses an Analytics configuration without IDFA support and integrates neither AdSupport nor App Tracking Transparency — iOS shows no tracking prompt.
- No selling of your data.
In the app, the advertising consent states (ad_storage, ad_user_data, ad_personalization) always remain denied, even after you enable usage data.
5.5. Who processes the data and where it goes
- Google Firebase / Google Analytics — processes usage data and crash reports under Google’s privacy policies.
- Google BigQuery — usage data is exported once per day to an analytics warehouse in PX Apps’ own Google Cloud project (located in Singapore); the export does not include advertising identifiers.
- Google Play (Android) · Apple App Store (iOS) — process purchases and Premium restoration under each store’s own terms.
We do not use Firebase for sign-in, cloud databases, or syncing your money book.
5.6. Retention
- Your money book and choices: on your device — no automatic expiry; you can delete anytime.
- Usage data (Google Analytics): 14 months at event and user level.
- Crash reports (Crashlytics): about 90 days per Firebase service documentation.
- Daily export to the analytics warehouse (Google BigQuery): tables currently expire after about 60 days under the project’s current configuration.
Retention applies to detailed data; standard aggregated reports are not necessarily deleted with it. If the retention configuration changes, we will update this policy.
5.7. Withdrawing your choice; the installation identifier
- Turning a switch off in Settings stops new collection from that moment.
- Turning it off does not immediately delete previously sent data; that data expires per section 5.6.
- Deleting app data or uninstalling deletes your money book on the device, but does not delete data already sent to Firebase.
- The data above is not tied to an account or your direct identity — the app has no sign-in. It is keyed to a random installation identifier, regenerated when you uninstall/reinstall the app or clear app data.
- There is currently no self-service process to link a deletion request to sent data, because that data is not tied to your identity. You can contact us for explanation and support.
6. Data when you contact support
When you email us or submit a support form, we may receive your name, email address, the content of your request, device information, app version and any files you attach. We use this only to receive, verify, respond, prevent abuse and improve support quality.
Do not send passwords, OTPs, card data, device keys or your full financial data. Please mask private information in screenshots.
7. App store services
The Apple App Store and Google Play may process account, device, payment, download, purchase and diagnostic information under their own policies. We do not receive your full payment-card details. We may receive transaction status or aggregate reports needed to activate and manage Premium.
- Android: Premium is purchased through Google Play Billing; restored through your Google Play account.
- iOS: Premium is purchased through the Apple App Store / StoreKit; restored through your Apple ID / StoreKit.
8. Device permissions
The app requests only the permissions needed for features you actively use. If a version lets you pick a file to import or export a backup, it accesses only the file/location you choose, within what the operating system allows. Any new permission must be explained when requested and reflected here.
9. Data sharing
We do not share local money-book contents because we never receive them. Usage data and crash reports (if you enable them) are processed by the providers listed in section 5.5 acting as service processors.
Support information may be shared only as necessary with our email/support infrastructure providers, with competent authorities upon lawful request, or to protect the rights and safety of users, ourselves and the community.
10. Retention and deletion
- In-app data: stays on the device until you delete transactions, clear app data, uninstall the app, or the device is reset.
- Backups you create: managed by you, at the location you chose.
- Usage data and crash reports (if enabled): per the retention list in section 5.6.
- Support information: kept as long as needed to handle the request, resolve disputes, prevent abuse and meet legal obligations; then deleted or anonymised.
You can delete data in the app or through your operating system settings. Because there is no user account and no server-side copy of your money book, we cannot restore local data once deleted.
11. Security
We apply data minimisation and appropriate technical measures within the app. However, no device or storage method is absolutely secure. Use a screen lock, keep your OS updated, avoid sharing your device casually, and keep your backups safe.
12. Your rights and choices
Within applicable law, you may request to know, access, correct, withdraw consent, restrict processing or delete personal data we actually hold. For data that lives only on your device, you exercise these rights directly through the app’s edit/delete functions or your OS settings.
For the two choices in section 5, you withdraw consent anytime by turning the corresponding switch off in Settings. For information already sent to support, contact sotienhomnay.app@gmail.com.
13. Children
Sổ Tiền Hôm Nay is not directed at children and does not knowingly collect children’s personal data. A parent or guardian who finds that a child has sent information to support may contact us to request review and deletion under applicable rules.
14. International transfers
We do not transfer local money-book data off your device. If you email support, enable the choices in section 5, or use Apple/Google services, information may be processed in another country (for example the analytics warehouse located in Singapore — section 5.5) under the relevant provider’s infrastructure and policies, consistent with applicable law.
15. Changes to this policy
We may update this policy when functionality, data handling or legal requirements change. A new version will state its effective date and be published at this URL. Where a change materially affects user rights, we will give notice by appropriate means before or at the time it takes effect.