Privacy Policy

Yarnstep is a crochet and knitting app for iPhone and iPad. Your patterns are your own, and we treat them that way. This page explains what the app and this website collect, why, and who else is involved.

Who we are

Yarnstep is made by Duy Bui, an individual developer based in Vietnam (“we”, “us”). This policy covers the Yarnstep app and the website yarnstep.com. For any privacy question, write to team@yarnstep.com.

Your patterns

• You choose which patterns to import: PDFs, photos or pages shared from another app. They are stored on your device and, if you turn on sync, in your own iCloud account through Apple’s CloudKit. We cannot open your iCloud data.
• Turning a pattern into guided rows starts on your device: the text is read from the page with Apple’s on-device text recognition. To split that text into rows and steps, the recognized text (not the PDF or photo) is sent to our server on Cloudflare and processed by Google’s Gemini model. The result comes back to your device.
• Our server does not keep your pattern text after the request is done. Google processes it only to answer the request, under paid API terms that do not allow it to train its models on that text.
• We never share, publish or sell your patterns, never build a pattern catalog from them, and never use them to train any model. Imported patterns cannot be shared or exported from Yarnstep to other people.
• “Ask about this row” sends the current row’s text and your question the same way, and follows the same rules.

What the app collects

No account, no personal details. Yarnstep has no sign-up and never asks for your name, email address, phone number or contacts.

Product analytics. To see which features help and to fix bugs, the app sends usage events and crash reports to PostHog in the EU, with IP addresses anonymized. Events say things like “import finished”, “row advanced” or “paywall shown”, with counts and durations. They never contain pattern text, page images, file names or designer names. Events carry a random identifier created on your device. If you answer the optional “Where did you hear about us?” question, that answer is sent too.

Approximate location. When an event arrives, PostHog estimates a country, region and city from the IP address and stores that estimate with the event; the IP address itself is dropped. Yarnstep never reads your device location.

Purchases

Yarnstep Pro is sold by Apple through the App Store. We never see your payment details, your Apple ID or your name. To turn on Pro, the app passes an anonymous app user ID and the App Store receipt to RevenueCat, which confirms the purchase. RevenueCat tells us about trials, renewals and cancellations so we can count them, linked only to that anonymous ID.

The website

• yarnstep.com is hosted on Cloudflare Pages. Cloudflare processes requests (including IP addresses) to serve the site and protect it from abuse.
• We use PostHog (EU) for website analytics, sent through our own domain. It records pages viewed, clicks on App Store buttons, the referring site and campaign tags (utm), with IP addresses anonymized and the same approximate-location estimate as above. Sessions may be recorded to see where pages confuse people; form fields are masked.
• One first-party cookie, ys_src, remembers for 180 days which site or campaign first sent you here, and PostHog keeps a random visitor ID in a cookie and local storage. Neither is used for advertising, and we do not sell or share this data.
• The free row counter keeps your count in your browser’s local storage. It never leaves your device.

Who else processes data

How long we keep data

Analytics events are kept for up to two years and then deleted. Pattern text is not kept on our server. Data in your iCloud account stays until you delete it.

Your choices and rights

• Delete a pattern in the app and it is removed from your device and from your iCloud copy. Deleting the app removes local data; your iCloud data can be removed in Settings, under your name, iCloud, Manage Storage.
• Wherever you live, you can ask us what we hold about you, or to delete it, at team@yarnstep.com. Events are tied to a random ID rather than your name, so tell us roughly when and on which device you used the app and we will find what we can.

Children

Yarnstep is not directed at children under 13, and we do not knowingly collect data from them.

Changes

If this policy changes, we will post the new version here with a new date. Material changes will also be noted in the app.