Privacy Policy - Wulang

1) Who we are

Wulang is provided by Saifullah Ahad ("we", "us", "our"). Our portfolio is saifullah.ai.

2) What Wulang does

Wulang creates a live vector lesson room between nearby Android devices. The teacher's device sends drawing operations to attending learner devices over the same local Wi-Fi network or an Android Wi-Fi Direct group. Attending devices can save the timed lesson for replay.

3) Data handled during a room

Wulang handles the following room data only to provide the active lesson:

• the four-digit room code and local network address needed to connect devices;
• vector stroke points, pressure, velocity, tool, colour, and timing;
• connection frames such as snapshot, acknowledgement, heartbeat, and catch-up data; and
• anonymous comprehension signals containing a random room-only token and a five-second timeline bucket.

This data travels directly between devices participating in the room. It is not sent to a Wulang cloud service, advertising service, analytics service, or developer-operated server. Wulang has no account, profile, roster, chat, public post, or student-name field.

4) Saved data

Each attending device can store its own lesson copy in Wulang's app-private storage. A saved lesson contains its title, start time, duration, timed stroke events, and anonymous signal buckets. Other apps cannot normally read these files.

Android device backup or device transfer can include Wulang lesson files only when Android's encryption requirements are available. This operating-system backup is controlled by the device owner and backup provider; the developer does not receive a copy.

5) Comprehension signals

A learner can tap "I'm lost." Wulang does not attach a name, account, device name, or profile to the signal. The random token changes between rooms. Duplicate taps from the same token in one bucket are deduplicated, and small totals are displayed to the teacher as a range so one learner is not singled out.

6) Permissions

• INTERNET and network/Wi-Fi state permissions provide local room discovery and socket transport.
• CHANGE_WIFI_MULTICAST_STATE supports Android NSD/mDNS room discovery.
• NEARBY_WIFI_DEVICES supports the optional Wi-Fi Direct path on newer Android versions.
• ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION are limited to Android 12 and earlier because those versions require them for Wi-Fi Direct discovery. Wulang does not read, infer, save, or transmit geographic location.
• Connected-device foreground-service permissions keep an active room connected when Wulang moves to the background. The service stops when the room ends.

Wulang does not request camera, microphone, contacts, calendar, phone, SMS, or broad storage access.

7) Data collection and sharing

The developer does not collect, sell, rent, or share personal data through Wulang. The app contains no advertising, analytics, authentication, crash-reporting, or tracking SDK. Local lesson transport is initiated by the teacher and learner devices and is limited to the room they join.

8) Retention and deletion

Live connection data exists for the active room. Saved lesson files remain on an attending device until the device owner clears Wulang's app storage or uninstalls Wulang. Clearing app storage and uninstalling remove local lessons and settings. Because the developer has no server copy, there is no remote account data to delete.

9) Feedback email

Choosing "Send feedback" opens the device's email app. Nothing is sent until the user chooses to send an email. Any email then follows the email provider's policy and is received at the public support address shown in this policy.

10) Children's privacy

Wulang can be used by tutors, parents, study groups, and learners, including children. It is designed without learner accounts, names, profiles, chat, public sharing, or behavioural tracking. Learner output is limited to a room-only anonymous comprehension signal sent to the teacher. We do not knowingly collect personal information from children or any other user. A parent, guardian, or teacher should supervise a child's use of nearby-device connections.

11) Security

Wulang validates frame sizes and checksums, deduplicates event identifiers, bounds relay hops, uses short-lived room codes, and stores lesson files in app-private storage. No system can eliminate every risk; users should create rooms only with people they intend to teach or join.

12) International transfers

Wulang does not send lesson data to a developer-operated service in any country. Device backup, a user-sent support email, or the local network chosen by the user can involve providers whose infrastructure is outside the user's country.

13) Changes to this policy

We may update this policy when Wulang's behaviour or legal requirements change. The current version will remain at privacy.saifullah.ai/wulang.html, with its effective date updated.

14) Contact

Privacy questions can be sent to Saifullah Ahad at [email protected].
Website: https://saifullah.ai
Location: Dhaka, Bangladesh