Privacy Policy
Last updated: 2026-09-24
SpindleMate is a calculator for machinists. It works without an account, and the jobs, machines, history and custom data you enter stay on your device. This policy explains the little data that does leave your device and why.
Data on your device
Machines, jobs, saved calculations, custom materials and your cutting data are stored only on your device (and, if you turn on iCloud sync in a later version, in your private iCloud database operated by Apple). We cannot access this data.
You can export all data as a backup file and delete everything at any time in Settings.
Feedback you send
When you send feedback, we receive the category, your message, your email address if you enter one, your language, the app version, the device model and the iOS version. If you report a calculation problem, the calculator, its inputs and results and the data versions are attached; you can see and remove them before sending. If you turn on “Attach diagnostics”, an anonymous diagnostic ID is attached so we can find the matching error log. The app does not let you combine this option with an email address, so the diagnostic ID and the logs found with it are never linked to you.
We use feedback only to answer you and to fix problems. Your email address is used only to reply. Feedback is stored in a database hosted by Cloudflare and is deleted 180 days after it has been handled, and in any case no later than one year after you sent it. You can ask us to delete it earlier in the app: Settings → Feedback; please mention the ticket number shown in the app.
Data updates and settings
The app downloads settings and, when we publish them, corrected reference data (thread, fit and material tables) from our server. These requests contain no personal data. Like any web server, our hosting provider sees your IP address; we do not store it. To prevent abuse we keep a salted, daily-changing hash of it for at most two hours.
Before sending feedback, the app obtains a random anonymous device token from our server. It is not linked to your Apple ID, your device identifiers or advertising identifiers.
Usage statistics and crash reports
To improve the app we collect anonymous usage events (for example which calculator was opened or whether a calculation succeeded) and crash reports, through our own statistics service and Google Firebase Crashlytics. They never contain the numbers you enter, part names, job names or material names. We do not track you across apps or websites, do not show ads and do not sell data.
This data is kept only as long as needed to operate and improve the app.
The app also keeps a diagnostic log on your device (error codes, timings and counts; never the numbers you enter or any names) for at most 7 days. It is not sent routinely: only when we investigate a problem can we request a time range for a given anonymous diagnostic ID, and the app then uploads that part of the log on its next start. Uploaded logs are kept for at most 90 days.
Purchases
Purchases are handled by Apple. We do not receive your payment details; the app only checks the purchase receipt issued by Apple on your device. Our anonymous usage statistics count purchase attempts (the product, the listed price and currency, and which screen led to it) without any link to your Apple ID.
Service providers
Cloudflare, Inc. (hosting of our server and the feedback database), Google LLC (Firebase Crashlytics crash reports) and Apple Inc. (App Store, iCloud). They process data on our behalf and only for these purposes.
Your rights
Depending on where you live (for example under the GDPR, the Korean Personal Information Protection Act or the Japanese APPI) you have the right to access, correct and delete your data and to object to its processing. Contact us in the app: Settings → Feedback. The app is not directed at children under 13.
If we change this policy, we will update the date above and describe important changes in the changelog.