Last updated: September 26, 2026
In short: Butterfly does not have user accounts and does not run its own servers for your data. The profile details you enter and every story you generate are stored only on your device. The only data that leaves your device is what's necessary to process a purchase through Apple and RevenueCat.
This page explains exactly what the app does and doesn't do, in plain language, so you can verify it yourself against how the app behaves.
Butterfly is made by Darwin Labs Ltd ("Darwin Labs," "we," "us"). This policy applies to the Butterfly app (bundle identifier com.darwinlabs.butterfly) on iOS and Android. If you have questions, contact us at hello@darwinlabs.dev.
Butterfly does not require you to sign up, log in, or create an account. The app has no backend server that receives, stores, or processes your profile information or the stories you write. Everything described below as "stored on your device" is saved using standard on-device local storage and never transmitted to Darwin Labs.
During onboarding (and any time you edit it afterward), Butterfly asks you for a short profile so it can tailor story suggestions:
This profile is saved only in the app's local storage on your device. It is never sent to Darwin Labs, and Darwin Labs never sees it. You can change or clear it at any time in the app.
The premises, choices, and stories you generate in Butterfly are created entirely on your device:
In both cases, the story content you generate is processed on your device and saved to your device's local storage. It is never uploaded to a Darwin Labs server or any third-party AI service.
Butterfly offers optional in-app purchases (a one-time full-access unlock and a per-story unlock). These purchases are handled entirely by:
We do not have our own payment processing and do not receive your card details or Apple ID directly; that information stays with Apple. For details on how these two companies handle data, see Apple's Privacy Policy and RevenueCat's Privacy Policy.
Butterfly does not include any analytics, advertising, or crash-reporting SDKs. We don't track your usage, show ads, or share data with ad networks.
Butterfly includes a "Delete All Data" option in the app that permanently erases, from your device, your profile, every story and choice you've generated, and the app's onboarding/model-setup state. Uninstalling the app has the same effect: since nothing is stored anywhere but your device, there is nothing left on our end to delete.
One exception: if you've already redeemed a paid single-story unlock, that unlock credit is not restored by "Delete All Data"; the app tells you this before you confirm the deletion. Your purchase history itself is retained by Apple and RevenueCat according to their own policies, not by us; contact Apple (via the App Store) if you need a record of a specific purchase.
Because we don't hold any of your profile or story data ourselves, there's nothing for us to look up or delete on our servers. If you have a question about data held by Apple or RevenueCat on your behalf, you're welcome to email us at hello@darwinlabs.dev and we'll help point you in the right direction.
Butterfly is not directed at children and is not designed to collect information from children. We do not knowingly collect personal information from children under 13 (or the relevant minimum age in your region). If you believe a child has provided information through the app, contact us and we'll help address it. As described above, any profile information entered lives only on that device and can be removed at any time using "Delete All Data."
If we change what this app does with data, we'll update this page and change the "Last updated" date above. We encourage you to check back occasionally.
Questions about this policy or how Butterfly works? Email hello@darwinlabs.dev.