Privacy Policy
Echo Korean listens to what you say in English, translates it into Korean, and reads it back to you, so that your ordinary conversations become Korean practice. This app is built and run by Tium Lab (티움랩), a small business in Korea. This page explains, in plain terms, what the app handles, where it goes, and how to get rid of it.
- No audio is ever recorded or stored. Speech becomes text and the sound is gone.
- Your sentences and their translations stay on your device by default.
- They are copied to the cloud only if you sign in, so your phone and computer match.
- The translation server does not keep the text of your sentences — it only counts how many you sent.
- There are no ads and no analytics. Nothing is sold or shared for advertising.
1. What the app handles
Your voice
The app needs the microphone to hear you. The audio is turned into text by the speech recognition built into your device or browser — the app never writes the sound to a file and never sends audio to our own servers.
Your sentences
Once your speech has become text, the app keeps a record of each sentence:
| What | Example |
|---|---|
| What you said, in English | Did you eat? |
| The Korean translation | 밥 먹었어요? |
| Date and time it was said | 2026-09-02 14:31 |
| Practice score and next review date | 88, due in 3 days |
| The 💡 explanation, if you asked for one | a short note about the grammar |
Romanization (bap meo-geo-sseo-yo?) is calculated on your device each time it is shown.
It is not stored anywhere.
If you write in 📔 My Korean diary, the English you wrote, its Korean translation and the date are stored the same way. Practice sentences you receive from 📌 Today's sentences and ✨ Sentences made for you are stored alongside your conversation sentences.
Sentences made for you (Premium, only when you ask)
When you tap ✨ Make 10 sentences for me, the app sends up to 40 of your most recent English sentences to our server so it can write Korean expressions that suit the way you talk. The server uses them only to write those sentences and does not store what you sent. It only counts how many times you used the feature that day, together with your account ID.
Payments
Premium is bought through Google Play. Google handles your payment details; the app never sees your card. To confirm a purchase, our server receives the purchase token Google issues, checks it with Google, and stores it with your account ID together with the subscription's end date and whether it renews automatically.
What we do not collect
- Location, contacts, photos, call logs or text messages
- Advertising ID (AAID) or other device identifiers
- Card numbers or other financial details (payments are handled by Google Play)
Your Google account, if you sign in
Signing in is optional for keeping records, but required for translation, because the server needs to know whose daily allowance to count. When you sign in, the app receives your account ID, email address, display name and profile picture from Google. These are used to show who is signed in and to keep your records separate from other people's.
Kept only on your device
Your settings (voice, speed, romanization on/off, and so on) and a daily total of how long you listened are stored in your browser's local storage. These are never sent anywhere — they exist only so the app can show you your weekly report.
2. Where it is stored
| Place | What is there | When |
|---|---|---|
| Your device browser storage |
Every sentence, translation, practice score, explanation, diary entry, settings, listening time | Always |
| Google Firestore Google LLC |
The same sentence records and diary entries, filed under your account ID
(users/{account ID}/sentences, users/{account ID}/diaries) |
Only while you are signed in |
| Google Firebase Authentication Google LLC |
Your sign-in itself (account ID, email) | Only while you are signed in |
| Our translation server Cloudflare, Inc. |
Your account ID, a date, and a number — how many sentences you sent that day (and how many times you used ✨ sentences made for you), and whether you are on the free or paid plan. For Premium, also the Google Play purchase token and the subscription end date. Your sentences and diary are not stored. | Each time you translate |
Sentence records and diary entries in Firestore are kept until you delete them or delete your account. The daily counts on the translation server are kept so that limits and billing work, and are removed when you delete your account.
3. Who else is involved
The app cannot work without these services. Nothing is shared with anyone else.
| Service | What it does | What it sees |
|---|---|---|
| Google Firebase Authentication, Firestore |
Signs you in and syncs your records between devices | Your account details and your sentence records |
| Cloudflare Workers & D1 | Runs the translation server and counts daily usage | Your account ID and the sentence or diary being translated, at the moment of translating (and up to 40 recent sentences if you ask for ✨ sentences made for you) |
| Cloudflare Workers AI | Produces the Korean translation, the 💡 explanations and the practice sentences | The text being processed. This runs inside Cloudflare and is not passed to a further company. |
| Google Gemini API | Backup translation, used only when Cloudflare's translation fails | The sentence or diary being translated — not your account ID |
| Google Play | Handles Premium payments and subscriptions | Your payment, under Google's own terms. We receive only the purchase token and subscription status. |
| Your device's speech engine usually Google on Android |
Turns your speech into text, and reads the Korean aloud | Your audio, as described in section 1 |
We do not use advertising networks or analytics tools, and we do not sell or rent your information to anyone.
4. Permissions the Android app asks for
| Permission | Why |
|---|---|
| Microphone | To hear what you say. This is the whole point of the app. |
| Internet | To translate and, if you sign in, to sync. |
| Notifications | To show the "Listening" notice while the app is running, and the optional morning reminder for today's sentences. You can turn the reminder off in Settings. |
| Run at startup | So the morning reminder stays scheduled after the phone restarts. |
| Google Play billing | To buy and restore a Premium subscription. |
| Foreground service (microphone) | So the app can keep listening while the screen is off. Android requires this to be declared. |
| Keep awake | So playback is not cut short when the screen turns off. |
The app never uses the microphone unless you have pressed Start. Pressing Stop ends listening and removes the notification.
5. Your choices, and how to delete everything
- Use it without signing in. Records stay on your device only, and nothing reaches the cloud. Translation will not be available, because it needs a signed-in account.
- Delete individual sentences — tick them in the list and press 🗑️.
- Export everything — Settings → Your records → “Export everything as a text file”.
- Delete your account and all data — Settings → 👤 → “Delete account and data”.
You will be asked to type
DELETEto confirm.
Deleting your account removes your sentence records and diary entries from Firestore, your usage counts from the translation server, and your sign-in from Firebase Authentication. Records held on your own device are cleared at the same time. This cannot be undone.
Full instructions, including how to ask by email instead, are on the account deletion page.
6. Children
Echo Korean is not directed at children under 13, and we do not knowingly collect information from them. If you believe a child has used the app and left information behind, write to the address in section 9 and it will be deleted.
7. Keeping it safe
- All traffic between the app and its servers uses HTTPS.
- The translation server rejects any request without a valid Google sign-in token.
- Firestore rules allow each account to read and write only its own records.
- No audio is ever written to storage.
No system can promise perfect security, but the app deliberately keeps very little: the server holds a count, not your conversations.
8. Changes to this policy
If what the app collects changes, this page is updated and the effective date at the top changes with it. Significant changes will also be announced inside the app.
9. Contact
Tium Lab (티움랩) · Business registration no. 168-31-01901
korea.jung0914@gmail.com
Questions, deletion requests and complaints are all welcome at that address.