Asymptote Privacy Policy

Introduction

Asymptote ("the app") is developed by Grisu Studio LLC. This policy is short because the app is simple: it draws mathematical pictures and short stories on your phone, and it has no accounts, no login and no servers of ours. Everything it remembers is written to your own device and stays there. The only data that leaves your phone is what Google's advertising SDK sends in order to serve the ads that keep the free version free, and you control whether that is personalised.

Scope

This privacy policy applies solely to the Asymptote mobile application.

Data We Collect

Stored on your device only, never transmitted to us: which stories you have marked with a heart, a count of the cards you have sent (the story and the time, never the recipient), the number of distinct days you have opened the app, and your settings (language, theme, sound, haptics, plot options). The name you type on a card is placed on that image and is not stored anywhere by the app. We also store the answer to the one-time age question as a bracket only — "under 13" or "13 or over". The birth year you enter is converted to that bracket and immediately discarded; the app never stores a date of birth. Collected by Google AdMob, not by us, in order to serve ads: your device advertising identifier (IDFA on iOS, Advertising ID on Android), IP address, coarse device information such as model and operating system version, and ad interaction data. We never collect your name, email address, phone number, contacts, location, or any account identifier — the app asks for none of them and has nowhere to send them.

How We Use Your Data

Your hearts are used to show you the stories you kept; the count of days visited is what opens the later stories. When you send a card, the image is created on your device and handed to the sharing menu of your phone; where it goes from there is between you and the app you choose. We have no analytics and no crash-reporting service, so we genuinely cannot see how you use the app. Advertising data is used by Google to deliver and measure ads. In the European Economic Area and the United Kingdom the app shows Google's consent form before any ad loads, and on iOS it shows Apple's App Tracking Transparency prompt. If you decline either one, ads still appear but are non-personalised. You can revisit and change these choices at any time from Settings → Privacy and ads. Ads are never shown over a story; a full-screen ad may appear only after a card has been sent. The app also caps the content rating of every ad it requests, so ads for gambling, alcohol, dating and similar adult categories are excluded regardless of your consent choices.

Children's Privacy

Asymptote is rated and listed for people aged 13 and over and is not directed to children. The app additionally asks a neutral, skippable age question at first launch; if the answer is under 13, ads are requested with child-directed treatment and no advertising identifier is transmitted. Only the bracket is stored, never the year.

Data Security

Because we run no servers and hold no database, there is no copy of your data for us to lose, to sell, or to be compelled to hand over. Everything the app saves lives inside its own sandbox on your device, protected by your device's own encryption and passcode. Uninstalling the app permanently deletes all of it, and Settings offers "Delete all my data", which erases every heart, count and setting the app has saved without uninstalling.

Changes to This Privacy Policy

We will update this policy whenever the app's behaviour changes in a way that affects it, and the "Last Updated" date above will change with it.

Contact Us

Questions, corrections or a request to delete data: email support@grisu.co with "Asymptote privacy" in the subject. Because all of your data is held on your own device, a deletion request is fulfilled by uninstalling the app or by using Settings → Delete all my data. We hold nothing to delete on our side, and we will say so plainly if you ask. Data handled by Google for advertising is governed by Google's privacy policy; the ad privacy choices inside the app let you withdraw consent at any time.

Account and data deletion

How to delete everything Asymptote holds — and what it holds in the first place.

Company Privacy Policy

For our general company privacy policy, see Grisu Studio.