Ström is a Swedish electricity price app made by Studio Cato. This policy explains what information we collect, how we use it, and how we protect it. Ström requires no account, no email address, and no sign-in. The app functions almost entirely with data stored on your own device, fetched from a public API.
Ström collects no personal information. Your preferences — chosen region, grid fee, and Pro status — are stored locally on your device in iOS UserDefaults and are never transmitted to our servers. Electricity price data is fetched directly from elprisetjustnu.se, a public Swedish API. We do not log or store the IP addresses or device identifiers of users fetching price data.
Ström includes an optional community device library where you can look up the running cost of household appliances. If you choose to contribute a device, the following information is submitted:
No name, account, or device identifier is attached to contributions. Submissions are stored as anonymous records and reviewed manually before appearing in the shared library. Do not include personal information in device maker or model fields.
Ström uses local notifications only — scheduled on your device by the app itself. No notification tokens are sent to or stored on our servers. Notifications fire when tomorrow's prices are fetched; they are generated and delivered entirely on-device by iOS.
The Pro upgrade is processed entirely by Apple via StoreKit 2. Studio Cato never sees or stores your payment information. Purchase status is verified through Apple's transaction receipts and persisted locally on your device. Restoring a purchase is handled through your Apple ID.
The device energy library is stored on Supabase, with servers located in the European Union. Supabase is GDPR-compliant and follows industry-standard security practices. Because contributions are anonymous, this database contains no personal data.
Ström does not sell or share personal data — because it collects none. The only external services the app communicates with are:
Device contributions to the community library are anonymous and cannot be linked back to you or your device after submission. If you submitted a device entry and would like it removed, contact us with the maker, model, and approximate submission date and we will delete it. Deleting the app from your device removes all locally stored preferences and cached price data immediately.
If we make material changes to this policy, we will update the date at the top of this page. We encourage you to review this policy periodically.
Questions about this privacy policy? Reach out at [email protected]. Studio Cato · studiocato.io