TeXBB is a Windows writing application with an optional Android companion viewer. It does not require a TeXBB account and does not use a developer-operated cloud service for document synchronization.
Developer and contact
- Developer: Kiyuob Jung
- Android package:
com.texbb.mobileviewer - Privacy contact: texbb@kiyuobjung.com
Android closed-test applications
If you request access to the Android closed test, we collect the Google Account email address that you voluntarily send to texbb@kiyuobjung.com. It is used only to add you to the Google Play tester list and for test-related communications.
The address is retained for the duration of the closed test and deleted when the test ends or upon your request, unless retention is required by law.
Information stored on your devices
The Android app stores the following in app-private storage:
- the paired computer's private-network address and TLS certificate fingerprint;
- an encrypted pairing credential protected by Android Keystore;
- offline Markdown, embedded images, PDF files, titles, sizes, hashes, and synchronization times;
- optional GitHub account and repository details, downloaded repository PDFs, and encrypted GitHub access and refresh tokens;
- automatic-sync and mobile-data preferences; and
- local synchronization status and abbreviated diagnostic records.
The Windows app stores its local TLS identity and pairing credential under the signed-in Windows account using Windows data protection. User documents remain in the user-selected TeXBB workspace.
Direct communication between your phone and PC
When you choose to pair the apps, TeXBB transfers snapshots directly between your Android device and your selected Windows computer over the local network. The connection uses HTTPS/TLS and the Android app verifies the exact certificate fingerprint shown by the pairing QR code. The persistent pairing credential is sent in an authorization header and is not placed in request URLs.
A pairing QR contains the private-network endpoint, the certificate fingerprint, and a short-lived, one-time invitation. If the computer changes address, TeXBB may use authenticated local-network discovery to locate the same paired computer. Document synchronization does not send documents or pairing credentials to a developer-operated server. Optional Windows issue reports are handled separately as described below.
Automatic synchronization and mobile data
- Auto sync controls automatic synchronization for both your connected PC and selected GitHub repositories.
- When Auto sync and Background sync are both On, Android can schedule synchronization while the app is not open.
- Use mobile data is Off by default.
- When it is Off, automatic document synchronization uses an eligible Wi-Fi or Ethernet connection.
- The Use mobile data setting applies only to automatic synchronization.
- Manual Sync with the PC or GitHub, sign-in requests, and Google Play operations may use the network currently selected by Android.
Optional GitHub repository connection
If you choose to connect GitHub, TeXBB opens GitHub in your browser so you can sign in and approve read access to the repositories you select. GitHub handles your account password. TeXBB receives a limited user authorization token, stores it in encrypted Android app-private storage, and uses it to list your permitted repositories and download PDFs directly from GitHub to your device.
A Cloudflare-hosted TeXBB authentication relay exchanges the authorization code and refreshes expiring GitHub tokens. It receives the code or refresh token only for that request and does not persist tokens or repository contents in an application database. The relay does not receive the PDFs. GitHub and Cloudflare may process network and security information under their own policies.
Selected repositories use the same Auto sync, Background sync and Use mobile data settings as your PC connection. You can also synchronize a repository manually by tapping Sync.
Disconnecting GitHub removes the saved account link, tokens, and selected repository list without deleting previously downloaded PDFs. You can clear local copies by clearing app data or uninstalling TeXBB. You can also revoke TeXBB's access in your GitHub settings.
Diagnostics
Diagnostic information is not uploaded automatically. Local Android records may include app versions, the PC address and port, synchronization timing and status, document counts, storage use, and abbreviated failure details. They exclude document contents and pairing secrets. Text is copied to the system clipboard only when the user selects a copy action.
Optional Windows issue reports
Help > Report an issue lets you choose whether to send a report. Selecting Send transfers your description, app version, report identifier, optional reply email address, and report ZIP over HTTPS through our Cloudflare relay and Resend to texbb@kiyuobjung.com. We use this information to investigate the issue and respond to you, not for advertising or marketing. Reporting is optional and is not required to use TeXBB.
- A screenshot is included only if you select one.
- Include diagnostics is Off by default. Turning it On adds redacted logs, settings, and system information. These may include file paths, document names, network addresses, and error details. Manuscript, bibliography, and PDF files are not automatically attached.
- Review your description and screenshots for private information. Redaction cannot remove every sensitive detail, and screenshots are not automatically redacted.
- Save ZIP creates a local copy without sending it, so you can inspect its contents first. Sending also keeps a local ZIP in your workspace; you can delete that copy yourself.
The relay processes report contents in memory and does not save the description, reply address, screenshots, or ZIP to its own database or application logs. To prevent abuse and duplicate delivery, it keeps report identifiers, content hashes, timestamps, and delivery status for a 30-day window. Attempt timestamps and a server-keyed hash of the connecting IP address are kept for a 24-hour rate-limit window; the relay database does not store the raw IP address. Expired records are removed by scheduled cleanup and subsequent requests, although platform interruptions can delay deletion.
Reports and replies in our support mailbox are retained only as long as needed to investigate and respond to the issue, unless longer retention is required by law. To request deletion, email texbb@kiyuobjung.com and include your report identifier if available. Deleting a local ZIP does not delete an already sent email.
Cloudflare, Resend, and our email provider also process delivery, security, and service information under their own terms and retention practices. This can involve processing outside your country. The relay's database limits above do not describe provider logs, backups, or email storage. See the Cloudflare Privacy Policy and Resend Privacy Policy.
Third parties
TeXBB contains no advertising, analytics, tracking, or separate crash-reporting SDK. Microsoft Store and Google Play may process purchases, installation, updates, security information, and platform diagnostics under their own terms and privacy policies. If you connect GitHub, GitHub processes your sign-in and repository access. See the GitHub Privacy Statement.
Retention and deletion
- A newly confirmed pairing replaces the previous pairing.
- A successful synchronization replaces the previous offline snapshot.
- Clearing Android app data or uninstalling the Android app deletes its locally stored data.
- Disconnecting the PC removes its saved pairing information but does not delete documents already downloaded to the device.
- Disconnecting GitHub removes the local connection and tokens but does not delete downloaded PDFs.
- After a complete successful repository sync, cached PDFs no longer present in that GitHub repository are removed from the device. An incomplete or failed sync does not trigger this cleanup.
- Deleting an individual repository from the GitHub library removes its connection and downloaded PDFs from the device after confirmation. The repository on GitHub is not changed.
- Deleting the Windows workspace removes its user documents; uninstalling alone may leave a user-selected workspace in place.
- Turning off PC sharing does not automatically delete offline copies already stored on a phone.
TeXBB has no user account or publisher-held document-synchronization database. Email addresses voluntarily submitted for Android closed testing and optional issue reports are handled as described above.
Android permissions
- Internet: communicate with the paired PC, GitHub, the optional authentication relay, and Google Play.
- Network state: determine whether a suitable network is available.
- Receive boot completed: restore scheduled automatic synchronization.
The Google Play build does not request camera, microphone, location, contacts, shared-storage, advertising-ID, or APK-installation access.
Changes and questions
This policy may change when TeXBB's features or data practices change. The date above will be updated. Questions may be sent to texbb@kiyuobjung.com.