Privacy Policy
Effective 13 October 2026
Starsign is an astrology app. This policy explains what it collects, why, how long we keep it, and how to have it deleted.
Who we are
Starsign is published by Tam Duc Studio, an individual developer in Vietnam, who is the controller of the data described here.
For any privacy question, or to ask us to delete your data, write to hamhansamu@proton.me. We answer within 30 days.
Who may use Starsign
You must be 16 or older. We do not knowingly collect data from anyone younger. If you believe a child has used the app, write to us and we will delete what we hold.
Your birth details stay on your phone
Your date of birth, and — if you enter them — your time and place of birth, are saved on your device only. We do not store them on our server.
To work out your Sun, Moon and rising signs, the app sends the date, the time, and the coordinates and time zone of the place to our server. The server calculates the three signs, returns them, and discards the birth details: they are not written to any database and are not recorded in our server logs. They are never sent to the language-model provider — readings are written from the signs alone.
When you search for your place of birth, the letters you type are sent to our server to look up matching cities. The search is not stored.
What we collect
A device identifier we create. The first time you open the app, our server issues a random identifier and a device secret. This is not your Google Advertising ID, and it is not linked to your name. It exists so that daily limits belong to this installation. Reinstalling the app creates a new one.
Your zodiac signs, when you ask for a reading. Horoscopes, compatibility readings and birth-chart readings are requested by sign — for example "Leo and Libra", or your Sun, Moon and rising signs — together with your interface language. Readings are shared by everyone with the same signs, so they are stored by sign, not by person.
Messages you send to an AI astrologer. Chatting requires signing in. The text you write, together with your Sun, Moon and rising signs, is sent to our server and on to our language-model provider so that a reply can be written. The conversation is stored on our server under your account, so that you can continue it. We do not use it for advertising and we do not sell it.
Your Google account, only if you sign in. Signing in is optional, and needed only to chat with an AI astrologer or to subscribe. If you do, we store the Google account identifier, and — when Google provides them — your email address and the web address of your Google profile picture. The identifier lets us recognise you as the same person on a different phone, so a subscription you paid for and trial messages you already used are not lost or reset. The email address and picture are shown back to you in Settings so you can tell which account you are signed in with. We store only the address of the picture, never a copy of the image. We never receive your Google password.
Purchases, if you buy Premium. Google Play gives the app a purchase token. We send it to Google to verify it is genuine, and we store the result — which plan you hold and when it expires — so the app knows your benefits. We never see your card number, and we do not receive your billing address.
Advertising data, if you consent. The free tier offers optional video advertisements from Google AdMob that you can watch to unlock a reading. What AdMob collects, and whether it may personalise ads, is governed by the consent choice you make in the dialog on first launch. Where that choice is required, you can change it at any time in Settings → Ad privacy options.
Basic diagnostics. Crash reports and anonymous usage events, such as whether a compatibility or birth-chart reading was opened, through Google Firebase. Your birth details and the text of your messages are never sent to analytics.
What else stays on your phone
Besides your birth details, the phone keeps the horoscopes it has already downloaded, your latest birth chart, your language choice, and the time of your daily reminder. The reminder is a notification scheduled on your phone; it does not come from our server.
Settings → Delete my data removes all of this from the phone at once. Uninstalling the app does the same.
Where your messages go
Readings and the replies of AI astrologers are written by a large language model operated by DeepSeek, on servers outside Vietnam and outside the European Economic Area. For a horoscope or a reading, only the signs and the language are sent. For a chat, your message and your three signs are sent. We do not send your name, your email address, your Google account identifier, your birth details, or any advertising identifier.
If you are in the EEA or the UK, this is a transfer of personal data to a third country. It happens because it is necessary to provide the reply you asked for.
How long we keep things
| Data | Kept |
|---|---|
| Birth date, time and place | Not kept on our server — calculated and discarded |
| Place searches | Not kept |
| The message and reply text held by our language-model gateway | 7 days, then deleted automatically |
| Metering records for those calls — model, token counts, cost, no content | Kept for cost accounting |
| Daily usage counters | 90 days |
| Rewarded-advertisement grants | 30 days |
| Conversations with AI astrologers | Until you ask us to delete them. There is no automatic expiry: these are your conversations, and you can continue them |
| Device identifier | Until you ask us to delete it |
| Google account link — identifier, email address, profile picture address | Until you ask us to delete it |
| Subscription records | While the subscription is active, and afterwards for as long as tax and accounting law requires |
Who we share it with
- DeepSeek, the language-model provider that writes the readings and replies. It receives signs, your chat messages, and your interface language.
- Google Play Billing, to verify a purchase and to run your subscription.
- Google AdMob, for the optional rewarded advertisements, subject to the consent choice you made.
- Google, for sign-in with your Google account, if you choose it.
- Google Firebase, for crash reporting and anonymous analytics.
The city search uses place data from GeoNames, which we copy onto our own server; your searches are not sent to GeoNames.
We do not sell personal data, and we do not share it with anyone else.
Your rights
You can ask us to give you a copy of what we hold about you, to correct it, or to delete it. You can withdraw your advertising consent at any time, and you can object to our processing. Write to hamhansamu@proton.me; we answer within 30 days, and using these rights costs nothing.
If you are in the EEA or the UK, we rely on these legal bases: performance of a contract to run the app and write the readings you ask for, consent for advertising and analytics, and legitimate interest to enforce usage limits and prevent abuse. You may complain to your national data protection authority.
If you are in California, we do not sell your personal information, and we do not share it for cross-context behavioural advertising beyond the advertising consent choice described above.
Deleting your account and your data
On your phone: open Settings → Delete my data. This removes your birth details, saved readings and reminder settings from the device immediately.
On our server: write to hamhansamu@proton.me and ask us to delete your data.
- If you signed in with Google, write from that email address, or tell us which one you used. We delete the account link, the email address, the profile picture address, every conversation tied to it, and the device identifiers attached to it.
- If you never signed in, our server holds no birth details and no messages from you — only the random device identifier and its usage counters, which expire on their own. Tell us you used the app as a guest and we will explain how to find that identifier if you want it deleted sooner.
- Uninstalling the app deletes everything stored on the phone, and makes the device identifier unreachable — but it does not by itself delete the records on our server. Ask us for that.
We complete deletion requests within 30 days. Records we must keep by law, such as proof of a purchase, are the one exception, and we will tell you if that applies.
Security
Traffic between the app and our server is encrypted with TLS. The language-model key exists only on the server and is never shipped inside the app. The device secret is held in your phone's secure keystore. No system is perfect; if we ever discover a breach affecting your data, we will tell you.
AI-generated content
Horoscopes, compatibility and birth-chart readings, and the replies from the AI astrologers are written by a language model. The positions of the Sun, Moon and rising sign are calculated, not written by AI. The AI astrologers are fictional characters, not real astrologers, and nothing they say is medical, financial, or legal advice.
Changes to this policy
If this policy changes in a way that matters, the app will show you the new version before you carry on using it. The date at the top always says which version you are reading.
Language
This policy is published in several languages. If a translation and the English version disagree, the English version prevails.