Last Updated: 2026-09-15
Kosaku Cards is built to keep your content on your device. We have no accounts, no login, and no server that stores the cards you make. This policy explains exactly what stays local, what leaves your device, and who else is involved when it does.
Card creation, layout, styling, image rendering and export all run locally. The following never leave your device:
We have no copy of any of it. If you delete the app, this data is gone with it.
Some features cannot work locally. Each one below is triggered by an action you take — none of them run in the background.
When you paste a link to import a post, that URL is sent to our link-parsing service so it can fetch the public content behind it. We process the request and return the result; we do not build a profile from it.
When you import readable text from a web page, the URL is sent to Jina Reader (a third-party service) to extract the article body. Only the URL is sent.
If you use the AI summary feature, the text you are summarizing is sent to our AI service, which forwards it to an upstream model provider to generate the summary. The text is processed to answer that one request and is returned to your device. We do not use it to train models. Do not put anything into the AI feature that you would not want leaving your device.
Picking a font downloads the font file from our CDN, or from the Google Fonts API if you browse Google Fonts. These requests carry the font name and standard network information such as your IP address. No card content is involved.
We use the following services to understand which features get used and to find crashes. They are configured to collect usage and device data, not your content:
The text of your cards is never sent to any of these services. On Android, Google Play Services may make an advertising identifier available to Firebase; we do not use it for advertising and we do not run ads in this app.
Subscriptions and one-time purchases are processed by Apple or Google — we never see your payment details. We use RevenueCat to check whether a purchase is active. RevenueCat receives a randomly generated app user ID, your purchase receipt and basic device information. That ID is not linked to your name or email. Redeem codes are validated by our own service using only the code itself.
Both are random values created on your device. They are not your device serial number, not your advertising ID, and they cannot be traced back to you. Reinstalling the app generates new ones.
We do not sell data, and we do not share data with advertisers.
Your cards live on your device for as long as you keep them. Requests to our link-parsing and AI services are processed to answer that request and are not retained as a record of what you made. Analytics and crash data are retained by Mixpanel and Firebase under their own retention policies.
Kosaku Cards is not directed at children under 13 and we do not knowingly collect personal information from them. The same protections in this policy apply to every user.
We may update this policy as the app changes. Updates are published on this page with a new "Last Updated" date. Material changes will also be noted in the app's release notes.
Questions, concerns or corrections — write to us and we reply within 24 hours: hugo3641@gmail.com