This page is the app-specific privacy policy for the mobile app Ultra Simple Expense Log. Doui Lab ("we") sets out the following policy regarding the handling of user-related information in this app.

1. Information we may store or process

The app stores spending records, categories, payment methods, notes, language settings, currency settings, and closing day settings on the device. Information required for premium entitlement checks, ad delivery, and purchase restoration may also be processed through third-party services.

2. Purpose of use

The stored or processed information is used to provide expense recording features, keep settings, show analytics, support import / export, respond to inquiries, prevent misuse, display ads, verify premium status, and improve the app.

3. Local storage

The core household expense data is stored in local device storage. Unless the user explicitly exports or restores data, the app is not designed around syncing bookkeeping data to an external server.

4. Third-party services

This app may use third-party services such as Google AdMob, Supabase Auth, RevenueCat, Apple App Store, and Google Play. These services may process information according to their own privacy policies. RevenueCat processes purchase history and entitlement status to provide premium access, restore purchases, and analyze subscriptions. The app does not send bookkeeping entries such as amounts or notes to RevenueCat or AdMob.

5. Personal information

The Android app optionally lets you sign in with an existing Doui Lab account using email and password. These credentials are sent to Supabase Auth for authentication. Session information is kept in protected device storage; the app does not save your password. RevenueCat receives an account ID instead of your email to check that account’s premium entitlement. Signing in or out does not send, move, or delete device-local expenses. You can also use the app without signing in.

The app does not require direct entry of name, address, phone number, or similar data. However, device identifiers or purchase-state-related information may be processed by third-party services for billing and advertising.

6. Advertising

Ads may be displayed via AdMob during free use. The advertising SDK may collect and share approximate location derived from IP addresses, ad and app interactions, diagnostic and performance information, and device identifiers such as advertising IDs. These are used for ad delivery, analytics, and fraud prevention, and are encrypted in transit. Premium use is designed to remove ads.

The Android app presents consent and privacy choices where required and starts ads after confirming that ad requests are permitted. Where privacy choices can be changed, an ad privacy option is available in Settings. You can also manage your advertising identifier in your device settings.

7. Stopping use and data deletion

If you want to stop using the app, please uninstall it. Device-local data will be removed from the device side. You are responsible for any exported backup files you keep. Uninstalling does not cancel a Google Play or App Store subscription; use the store’s subscription management to cancel it. Third-party purchase information may be retained under the provider’s policy for restoration, fraud prevention, and related purposes. For contact, please review the support page.

To request deletion of an account used for optional sign-in and its associated information, see the account deletion instructions. Deleting an account does not automatically delete expenses on your device or cancel store subscriptions.

8. Revisions

This policy may be updated when necessary. If there is a material change, it will be announced on this page.

9. Contact

Please review the support page.