This is the privacy policy for Jindo, an iOS app that helps you learn Korean through spaced‑repetition flashcards. We've tried to write it in plain English rather than legalese. If something is unclear, email us at [email protected].
Jindo is operated by Lead Logger LLC, a limited liability company organized under the laws of the State of Illinois, United States ("Lead Logger," "we," "us"). For privacy‑related requests, contact us at [email protected].
Jindo is designed to need as little personal data as possible. We do not ask for your name, email, phone number, address, or date of birth. We do not require an account.
Everything you do inside the app — the cards you've reviewed, your daily streak, your spaced‑repetition history, which lessons you've completed, your daily goal — is stored locally on your iPhone using Apple's SwiftData framework and UserDefaults. We never receive this data on a server we control.
When you first open Jindo, the app asks a small number of multiple‑choice questions to personalise your experience. Your answers are stored on your device and sent to our analytics provider (PostHog, see §4) so we can understand how different kinds of learners use Jindo. The questions and their possible values are:
| Question | Possible values |
|---|---|
| Why are you learning Korean? | K‑pop, K‑dramas, travel, friend or partner, living in Korea, just curious |
| How did you hear about Jindo? | TikTok, Instagram, YouTube, friend, Google, App Store, other |
| What's been holding you back? | Multi‑select from: forgetting words, dry textbooks, dialogue speed, Hangul looks intimidating, plateau after basics, no time |
| How much Korean do you know? | None, a few words, some phrases, basic conversation |
| Tried other apps before? | Multi‑select from: Duolingo, LingoDeer, Drops, Talk To Me In Korean, "None — Jindo's my first" |
| Why didn't they stick? (conditional) | Multi‑select from: too slow, boring, no real Korean content, couldn't read Hangul, felt like school, lost motivation |
| What's the dream? | Sing K‑pop, watch K‑dramas raw, talk to partner, travel Korea, read webtoons, love the language |
| What do you want to understand? | Multi‑select from: K‑pop lyrics, K‑drama dialogue, food, webtoons, travel basics, daily conversations |
| How much time per day? | An integer between 5 and 30 (minutes per day) |
| Demo result | How many of the 3 sample cards you marked "got it" |
You cannot type free text in onboarding; every answer is one of the values above.
To link analytics events with subscription events on the same install, Jindo generates a single pseudonymous identifier on first launch — Apple's identifierForVendor if available, otherwise a random UUID — and stores it in UserDefaults. The same ID is used as the PostHog distinct_id and the RevenueCat appUserID. It is not your Apple ID, name, or email. Deleting and reinstalling the app generates a new ID.
We do not use Apple's advertising identifier (IDFA) and do not present an App Tracking Transparency prompt.
Jindo uses PostHog Cloud (US region, host https://us.i.posthog.com) to capture product‑analytics events. The events currently sent include:
app_launched — when the app starts.onboarding_<step_id> — one event per onboarding screen completed, with your answer for that screen.onboarding_completed — a summary event with all onboarding answers (the fields in §2.2).intro_page_viewed, intro_match_completed — first‑run Hangul tour events.post_intro_notifications_prompt_shown, post_intro_notifications_prompt_responded — the in‑app reminder opt‑in.chapter_selected, chapter_viewed, session_started, review_session_started, session_completed, card_rated, review_prompt_shown — study activity events. Properties include chapter and lesson identifiers, card counts, and your card rating (again/hard/good/easy), but never card content or free text.paywall_viewed, paywall_plan_selected, paywall_dismissed, subscription_started — paywall and purchase events.daily_goal_changed — when you adjust your daily card target in Settings.captureApplicationLifecycleEvents option.In addition, the PostHog SDK attaches contextual properties to each event — device model, iOS version, app version, locale, time zone, and the pseudonymous distinct ID described in §2.3. PostHog does not receive your IDFA.
PostHog stores these events on its servers in the United States. See PostHog's own policy at posthog.com/privacy.
Jindo offers an optional paid subscription. Payments are handled by Apple through the App Store, and subscription state is managed by RevenueCat. We never see your credit card, Apple ID, or billing address — Apple does.
RevenueCat receives the pseudonymous identifier described in §2.3 (as the appUserID) and the StoreKit receipt for your purchases. RevenueCat stores subscription state on its servers in the United States. See RevenueCat's privacy policy for details.
Because subscriptions are tied to your Apple ID, premium status follows your Apple ID across devices. Study progress, however, is stored only on the device where it was made.
Jindo can send local reminders to help you keep your streak (e.g. a daily nudge or a weekly recap). These are scheduled on your device using Apple's UNUserNotificationCenter APIs. We do not send push notifications from our servers and do not register for an APNs device token.
The app asks for notification permission at a single in‑context moment after the first Hangul lesson. You can change this any time in iOS Settings → Notifications → Jindo. Declining has no effect on the rest of the app.
| Service | Purpose | What they receive |
|---|---|---|
| Apple (App Store, StoreKit, iOS) | App distribution, payment processing, on‑device frameworks | Whatever Apple receives as the platform owner. See Apple's privacy policy. |
| PostHog (US) | Product analytics | The events and properties listed in §3, plus SDK context (device, OS, app version, locale, time zone) and the pseudonymous distinct ID. See PostHog's privacy policy. |
| RevenueCat (US) | Subscription management | The pseudonymous appUserID and the StoreKit receipt for your purchases. See RevenueCat's privacy policy. |
We do not share data with advertising networks, data brokers, or any other third party. We do not sell your data.
Although Lead Logger LLC is established in the United States, we process personal data of users in the United Kingdom and the European Economic Area in accordance with the UK GDPR and the EU GDPR when they use the App. Our legal bases are:
If you are a resident of California or another US state with a comparable privacy law (such as Colorado, Connecticut, Virginia, or Utah), the following applies:
To exercise any of these rights, email [email protected].
Depending on where you live, you may have the right to access, correct, delete, or port your personal information, and to object to or restrict our processing of it. Because we do not collect names, emails, or other identifying information, the practical way to exercise these rights is to email us at [email protected] with enough context to identify your install — for example, the approximate date you started using the app, the device you used, and your onboarding answers (motivation, level, daily time goal).
Jindo is not directed to children under 13 (or under 16 in some jurisdictions). We do not knowingly collect personal information from children.
We rely on the security features of iOS (sandboxed app storage, your device passcode, file protection) to protect data on your device. Network requests to PostHog and RevenueCat are made over HTTPS. No method of transmission or storage is 100% secure; we cannot guarantee absolute security.
Lead Logger LLC is based in the United States. PostHog and RevenueCat also process data in the United States. If you use Jindo from outside the United States — including from the United Kingdom, the European Economic Area, or Switzerland — your information will be transferred to and processed in the United States. Where required by the UK GDPR or EU GDPR, such transfers are made in reliance on the European Commission's Standard Contractual Clauses (and the UK Addendum, where applicable) entered into between Lead Logger LLC and our service providers under their respective data‑processing terms.
If we make material changes, we'll update the "Last updated" date at the top and, where appropriate, surface a notice inside the app.
Privacy questions, complaints, or data requests: [email protected].