Privacy Policy

Clef for iOS: what's stored, and where

Clef for iOS needs no account and no sign-up. Your practice data, drill sessions, streaks, accuracy history, and the spaced-repetition scheduler's due dates, is stored locally on your device using Apple's SwiftData framework. If you have iCloud enabled on your device, that same data syncs through your personal iCloud account (via CloudKit) so it carries over to your other devices signed into the same Apple ID. That sync is between your device and your own iCloud account; we don't have a server that receives, stores, or has access to your practice data.

Notifications

If you opt in, Clef for iOS can send local practice-reminder notifications, scheduled entirely on your device using iOS's local notification system. These aren't sent from a server and don't involve any third party. You can turn them off any time in iOS Settings > Notifications > Clef.

Purchases and subscriptions

All purchases, the Annual and Monthly subscriptions and the one-time Lifetime unlock, are handled entirely by Apple through StoreKit / In-App Purchase. Clef never sees or stores your card number, billing address, Apple ID password, or any other payment detail. Apple shares only what's needed to unlock the purchased features in the app (essentially, a receipt confirming what you bought); see Apple's own privacy policy for how Apple handles payment data.

What the web trainer collects: nothing that leaves your browser

The name-the-note drill at clefdrills.com needs no account and no sign-up. Your current session's score, streak, and accuracy exist only in memory while the page is open. The one thing that persists between visits, your best streak, is saved with the browser's localStorage API, on your device only. We have no server-side record of it, no way to see it, and no way to associate it with you.

Legacy email signup (website only)

Earlier versions of this website ran an email signup form so visitors could be notified when Clef for iOS launched. That form is no longer shown on the site now that the app is live. If you signed up previously, or if you reach the underlying endpoint directly, any email address collected was processed through Resend, our transactional email service, solely to send a confirmation and a single launch notice. We don't use it for anything else, and you can ask to have it deleted at any time; see the contact section below.

The analytics we run, and why

Every page on this site loads a small first-party analytics script, hosted on our own server, so we can see how many people visit and which pages they read. It's Umami, an open-source, cookieless analytics tool. It runs from clefdrills.com/stats, our own domain, not a third-party tracker's. This applies to the website only; Clef for iOS does not run this or any other analytics script.

• No cookies. Umami identifies a "visit" using a rotating daily hash of your IP address and browser, not a cookie or device identifier stored on your machine.
• No individual tracking. We see aggregate counts (visits, page views, referrers, rough country and browser), never a profile tied to your name or email.
• No third parties. The data lives on our own server and is never sent to Google, Meta, an ad network, or any other outside company.

What we don't do

• No advertising cookies, no cross-site tracking, no ad-network pixels, no selling or renting of email addresses, practice data, or analytics data to third parties.
• No account system anywhere in Clef, on iOS or the web, so there's no password, profile, or persistent identity tied to you on our servers in the first place.
• No third-party analytics or tracking SDKs inside Clef for iOS itself.

Your rights: access, correction, deletion

Your Clef for iOS practice data lives on your device (and your own iCloud account, if enabled); deleting the app, or turning off iCloud sync for Clef, removes it. Because we hold no copy of it ourselves, there's nothing on our end to request or delete for app data. For any legacy email address on file from the old signup form, email [email protected] to ask what we have, correct it, or have it deleted outright. We aim to handle these requests within a few business days.

Children's privacy

Clef is not directed at children under 13, and we don't knowingly collect personal information from anyone under that age. Neither the app nor the web trainer requires any personal information to use. If you believe a child has submitted information through the legacy signup form, contact us and we'll remove it.

Changes to this policy

If what we collect changes, we'll update the "last updated" date at the top of this page and describe the change here before it takes effect.