Yonda ("Yonda: Read Real Japanese") is a manga-reading and Japanese-learning app. You scan pages from real manga, Yonda reads the Japanese text and helps you understand it, and it tracks what you've learned over time. This policy is written to be specific about what's captured, where it goes, and who can see it.
Yonda is built and operated by Jeremy Irons (sole developer). Contact: support@irons.la.
If you use the in-app AI conversation feature to ask questions about scanned text, your messages and the text you're asking about are sent to Anthropic's Claude API to generate a response, for the same purpose and under the same no-training terms described above.
Yonda offers optional paid subscriptions (and a lifetime purchase). Purchases are handled entirely by Apple's In-App Purchase system. We receive confirmation of your subscription status and purchase history so we can unlock the features you paid for — we never see or store your payment card details, which stay with Apple.
We use PostHog to understand how the app is actually used, so we know what to fix and what to build next. PostHog receives a stream of small events such as: the app was opened, a study session started or finished (with how many items and what accuracy), a card was answered (which exercise format, right or wrong, how many milliseconds it took), a page was scanned, the subscription screen was viewed, and you signed in or signed out.
Those events are labelled with your random user ID (the same UUID described above), coarse attributes (your JLPT target level and subscription tier), and standard device and app information the SDK collects automatically: app version, device model, OS version, locale, and a device identifier generated by PostHog. This identifier is not Apple's advertising identifier (IDFA); we do not request or use the IDFA.
What PostHog never receives: your email address, your display name, anything you type into the AI Conversation, your answers, any Japanese text you study, and any photo you take or its contents. We send counts, timings and category labels — never content. Session replay is switched off and will stay off: the app shows pages you photograph, and recording the screen would capture exactly the material we promise not to collect.
Data is sent to PostHog's US cloud. It is used only to improve the app — not sold, not used for advertising, and not linked to advertising identifiers.
Account information, study data, and scan photos are stored using Supabase (Postgres database and file storage), our backend provider. Photos live in a private, per-account storage bucket protected by row-level security, so only your account can read or write your own files.
That's the entire list. We do not sell or rent your data, and we do not use advertising SDKs.
Your account, scans, and study data are kept for as long as your account exists. If you delete your account, your data is deleted from our active systems; backups may retain data for up to 30 days after deletion before being overwritten.
If you live in the EU, UK, or California, you have additional rights under GDPR, UK GDPR, and CCPA, including data portability and the right to complain to your local data protection authority. Email us to exercise any of these rights.
Yonda is not directed at children under 13, and we do not knowingly collect data from anyone under 13. If we learn that a child under 13 has an account, we will delete it.
We use industry-standard practices (encryption in transit, per-account access controls on stored files) to protect your data. No system is perfectly secure, but we take reasonable steps to protect what you share with us.
If we change this policy, we'll update the effective date at the top. Material changes will be surfaced in the app before they take effect.
Questions, requests, or concerns: support@irons.la.