Privacy Policy

Lingo15: Chinese & German · Android · version 1.1 and later · Last updated 17 October 2026

In short: Lingo15 works without an account. Your progress stays on your phone. If you choose to sign in with Google, a copy of your progress is stored under your Google account so you can continue on other devices. You can delete that copy and your account at any time. The app shows ads through Google AdMob. We never sell personal information.

1. Who we are

Lingo15 is made by HomiLabs ("we", "us"). Contact: homilabs.smc@gmail.com. Earlier version 1.0 had no sign-in; this policy covers version 1.1 and later, and the summary for all HomiLabs tools is at tools.homilabs.org/privacy.

2. What stays on your phone

What	Why	Leaves your phone?
Your progress: lessons done, words and their review schedule, study days and time, streak, characters written, chosen level, settings	So your learning continues next time.	Only if you sign in (see section 3)
Microphone (optional)	For speaking practice. In most exercises your speech is turned into text by your phone's own speech recognition service (usually Google's). In the "Accent and intonation" exercises Lingo15 itself listens for a few seconds and compares the melody and rhythm of your voice with the app's voice, entirely on your phone; the recording stays in memory only while it is being compared and is then discarded. Lingo15 never keeps, uploads or receives your voice.	No (by Lingo15); speech recognition is handled by your device's speech service
Text-to-speech	To read words aloud with the voices on your phone.	No (by Lingo15)
Vibration	Optional light feedback on answers.	No

3. Optional account and cloud backup

Signing in is optional and is offered in Settings → Backup and sync. If you sign in with Google:

What we store	Where	Why
Your Google account identifier, email address and display name (as provided by Google)	Firebase Authentication (Google)	To sign you in and link your backup to you.
A backup of your progress: lessons done, words and review schedule, study days and time, streak freezes, count of characters written, chosen level	Cloud Firestore (Google), stored in the United States (multi-region)	To restore your progress and to continue on other devices.

We do not store your voice, contacts, photos, location or files, and the backup contains no messages or free text from you. We do not use your account or backup for advertising, and we do not share your email address with advertisers. Only you (signed in as yourself) can read or change your backup, enforced by security rules on the database. Data is encrypted in transit, and Google encrypts it at rest.

Your device and the cloud copy are merged, never overwritten: lessons completed on any device are kept, and for each word the most recently studied record is kept.

4. Advertising

Lingo15 shows banner, interstitial and optional rewarded ads through Google AdMob. We ask Google to show only ad content rated suitable for all audiences, including families. Google may collect the device's advertising ID, approximate location derived from the IP address, and how you interact with ads, and may use these to personalise ads. In the European Economic Area, the UK and Switzerland, and where else required, you are asked for consent first and can change your choice later in Settings → Ad privacy choices. See how Google uses data from apps that use its services. You can reset or delete your advertising ID in your phone's Settings → Privacy → Ads (or Settings → Google → Ads).

5. Permissions

Microphone – only for speaking practice, asked when you first use it. Nothing you say is stored or sent by Lingo15.
Internet and network state – for ads, sign-in and cloud backup.
Advertising ID – used by Google AdMob.

6. Who else handles data

Lingo15 uses Google services as service providers: Firebase Authentication and Cloud Firestore (sign-in and backup), Google AdMob (ads), and your device's speech service. We do not sell personal information and do not share it with anyone else, except where the law requires. Google may process data in the United States and other countries under its own safeguards (see Firebase privacy).

7. How long we keep it

Device data stays until you clear the app's data or uninstall. Your cloud backup and account are kept until you delete them (section 8) or reset a language, which also removes that language's backup.

8. Your choices and rights

Use the app without signing in. Nothing is lost by not having an account.
Sign out in Settings. Your progress stays on the device.
Reset a language in Settings. This also clears that language in the cloud if you are signed in.
Delete your account and cloud data in Settings → Backup and sync → Delete account and cloud data. Without the app, follow these steps.
You may ask us for a copy of your data or ask us to correct or delete it, and, where the law gives you these rights, to restrict or object to its use or to complain to your data protection authority. Write to homilabs.smc@gmail.com; we reply within 30 days.

9. Children

Lingo15 is intended for people aged 13 and over. We do not knowingly collect personal information from children under 13. If you believe a child has signed in, contact us and we will delete the account.

10. Changes

We update this policy before a version that changes what the app uses is released. The date above shows the latest change.

Contact

HomiLabs · homilabs.smc@gmail.com