Under Trees - Private diary - Privacy Policy
Last updated: September 22, 2026
This Privacy Policy describes how Under Trees - Private diary, package name net.langhoangal.undertrees (the "App") handles information when you use the App.
The App is provided worldwide on Google Play and the App Store by Lang Hoang, an independent app developer based in Vietnam ("I", "me", or "my").
This policy explains what types of data may be collected, how that data is used, and how off-device processing is protected.
1. Account Access
Creating an account is optional and only applies to features that explicitly require sign-in.
Authentication provider: Google.
The local journal does not require a user-facing account on Android or iPhone. Google sign-in is optional and used only when you choose backup and restore. The Android release may create an anonymous Firebase session for supporting services.
2. Children's Privacy
The App is not directed to children under 13. The minimum recommended age for using the App is 16. It is not declared as a child-directed or Families app on Google Play. If you are a parent or guardian and believe a child has provided personal information directly to me, contact me so I can take appropriate action.
3. Local Device Data
The app stores some information locally on your device.
Core journal content, attached media, tags, affirmations, themes, security settings, reminders, and preferences are stored on your device. Local journal and media storage is not encrypted by the app passcode.
- Journal entries and organization:
Entry titles and text, dates, moods, formatting, tags, affirmations, and related journal records are stored in the app's local database.
- Photos and drawings:
Media attached to entries is copied into the app's private local media folder.
- Security settings and preferences:
Security settings and preferences are stored in platform-protected app storage. Android protects encrypted preferences with Android Keystore; iPhone applies iOS complete file protection to private journal data. The app passcode controls access through the app interface and does not independently encrypt journal files or exported backups.
4. Types of data that may be collected and processed outside your device
Optional Google account information
Your Google account identifier, name, and email address may be processed to authorize access to the app-specific Google Drive backup area.
Details
- Category: Personal info
- Type: User IDs, Email address, Name
- Collected: Yes
- Shared: No
- Required: No
- Purposes: App functionality, Account management
- Processed by:
- Notes:
Processed only when you choose Google sign-in for backup and restore.
Optional Google Drive backup
A backup can contain journal entries, dates, moods, formatting, tags, affirmations, and related journal data. It is uploaded only when you start a Drive backup. Attached photos and drawings may be included with a user-initiated Google Drive backup.
Details
- Category: App activity, Photos and videos
- Type: Other user-generated content, Photos
- Collected: Yes
- Shared: No
- Required: No
- Purposes: App functionality
- Processed by:
- Notes:
Journal database content is uploaded only when you explicitly create a backup.
Photos and drawings attached to journal entries are uploaded only when you explicitly create a backup.
Purchase and subscription data
Purchase and subscription records may be processed to validate Premium access and restore purchases.
Details
- Category: Financial info
- Type: Purchase history
- Collected: Yes
- Shared: No
- Required: No
- Purposes: App functionality
- Processed by: ,
- Notes:
Used to validate Premium access and restore purchases.
Anonymous app identifier
An anonymous Firebase identifier may be processed for supporting app services without creating a user-facing account.
Details
- Category: Personal info
- Type: User IDs
- Collected: Yes
- Shared: No
- Required: No
- Purposes: App functionality, Analytics
- Processed by:
- Notes:
The release app may create an anonymous Firebase session. It does not require you to provide a name, email address, or password.
Device and app identifiers
Technical identifiers may be processed for analytics, remote configuration, and related app operations. Technical identifiers may be processed for advertising, fraud prevention, and measurement when ads are shown.
Details
- Category: Device or other IDs
- Type: Device or other IDs
- Collected: Yes
- Shared: Yes
- Required: No
- Purposes: Analytics, App functionality, Advertising or marketing, Fraud prevention, security, and compliance
- Processed by: , ,
- Notes:
Used for analytics, remote configuration, and related app operations.
Used for ad delivery, measurement, and fraud prevention where ads are available.
App usage and interactions
Basic feature interactions may be processed to understand usage and improve the app; the app's named analytics events do not include your journal text. Interactions with ads may be processed for delivery, measurement, and fraud prevention.
Details
- Category: App activity
- Type: App interactions
- Collected: Yes
- Shared: Yes
- Required: No
- Purposes: Analytics, Advertising or marketing, Fraud prevention, security, and compliance
- Processed by: ,
- Notes:
Feature events such as adding or reading an entry, searching, selecting a theme, and managing tags or affirmations may be measured. Journal text is not sent in these named events.
Ad-related interaction telemetry may be collected by the advertising SDK.
Crash data
Crash reports may be processed to diagnose problems and improve app stability.
Details
- Category: App info and performance
- Type: Crash logs
- Collected: Yes
- Shared: No
- Required: No
- Purposes: Analytics
- Processed by:
- Notes:
Used to diagnose crashes and improve app stability.
Diagnostics data
Technical diagnostics may be processed by platform services to monitor app quality.
Details
- Category: App info and performance
- Type: Diagnostics
- Collected: Yes
- Shared: No
- Required: No
- Purposes: Analytics
- Processed by:
- Notes:
Technical diagnostics may be processed by .
6. Service Providers
7. Security
I use reasonable administrative and technical measures appropriate to the information handled directly by me.
Information transmitted to the services described in this policy is sent using their SDKs and encrypted network connections where supported.
No method of electronic transmission or storage is completely secure, and absolute security cannot be guaranteed.
8. Data Retention
Local journal data remains on your device until you delete it, clear app storage, or uninstall the app. User-created backups remain in the app-specific Drive area until you remove them or your Google account policy removes them. Provider-processed purchase, advertising, analytics, authentication, and diagnostics data follows each provider's policy.
Local data: Delete individual entries and related media in the app, or remove all local app data by clearing storage or uninstalling.
Server data: backups remain under your Google account in the app-specific data area until deleted. The app may retain an anonymous Firebase identifier through according to Firebase policy.
Third-party data: , , Firebase services, , , the , and retain data according to their own privacy and retention policies.
9. Data Deletion
Delete individual entries and backups from the relevant screens in the app. To remove all local journal data, clear the app's storage in Android settings where available or uninstall the app on Android or iPhone. backups are associated with the Google account you chose and can be removed from the backup screen where available; Google, Apple, and other providers may retain provider-processed data under their own policies. Email support if you need help identifying the applicable deletion path.
View data deletion instructions
10. Contact
For privacy questions, contact:
Email:support@langhoangal.dev
Journal storage and app lock
Under Trees stores the journal database and attached media in the app's private local storage. The passcode and supported biometrics restrict access through the app interface; they do not independently encrypt the journal database, media files, local backups, or backups. Android protects encrypted preferences with Android Keystore. On iPhone, Under Trees applies iOS complete file protection to its private journal and theme files while they remain inside the app container.
Optional Google Drive backup
access is optional on Android and iPhone. When you sign in and create a backup, the app uploads a copy of the journal database and referenced media to 's app-specific data area. These backups are protected by your Google account and transport encryption, but they are not end-to-end encrypted by Under Trees. Both platforms also support local file backup and restore through the device's file picker or share flow.
Advertising, analytics, and purchases
The free Android and iPhone versions may use for ads, and Remote Config for app usage and configuration, and with the applicable platform store for Premium purchases. On iPhone, tracking or personalized advertising is requested only after the applicable consent and App Tracking Transparency choices. Premium removes in-app ads.