Privacy Policy

Last updated: October 15, 2026

This policy covers the Terminus app for iPhone and iPad, and this website with its waitlist. Serhii Kucherenko, an individual developer in Vancouver, Canada, makes Terminus and is responsible for the data it collects.

In the app: what stays on your device

Your sets, cards and answers, and the dates of your tests, stay on your device, in the app and its widgets, unless you connect an AI (below). Without it, Terminus has no account, so none of them leave your device. Text you share into Terminus from another app, and cards you add with Siri or Shortcuts, are read and saved on your device. Your setup answers (your daily goal, the number of days to your test, and your reminder choice) are sent as the events below, never with a date. A list you paste is read on your device. Reminders are notifications that your device schedules.

The app shows no ads and does not track you across other companies’ apps and websites.

In the app: Connect an AI

Settings, Connect an AI lets Grok, Claude or ChatGPT read your sets and cards, add cards, fix definitions and rename sets. Terminus asks you before any card is removed. It is the one part of Terminus with an account, and only you can turn it on. The account is anonymous: you do not sign in, and Terminus asks for no name and no email address. Your device makes the account, and shows a code of 8 letters and digits that you type when your AI asks for it; the code works once, for 10 minutes. While you are connected, your device sends a copy of your sets and cards to our server, so the AI can read them. The changes the AI asks for wait on the server until Terminus on your device takes them. Then the server deletes them.

• A random account ID, and a scrambled copy of the key your device uses, to know your device and your AI: until you disconnect, or 180 days after your device last reached the server.
• A scrambled copy of the code: until it is used, and at most 10 minutes.
• The names of your sets, their numbers of cards, and how many are new, learning and known, so the AI can name a set: until your device sends the list again, or you disconnect.
• A copy of the cards in your sets (each term and definition), encrypted with a key for your account alone, so the AI can read them: until your device sends that set again, you delete the set, or you disconnect.
• The text of the cards the AI sends and the changes it asks for, encrypted the same way, to carry them to your device: until your device takes them, and at most 30 days.
• The AI’s name (for example “Grok”), to show who made a change: with each change.
• Your IP address: Cloudflare sees it, as every server does. We do not store it.

The server never gets your answers, your reviews, the dates of your tests or your email address. Disconnect and delete account deletes all of the above at once.

The AI service you connect (xAI for Grok, Anthropic for Claude, OpenAI for ChatGPT) sees what you type to it and what our server answers: the names of your sets, their numbers of cards, and the cards it reads. That is between you and that service, under its own terms and privacy policy.

In the app: what it sends

So that we can see what works, the app sends these usage events to PostHog, and no others:

• onboarding_step: the number of the setup step you reached when you first opened the app.
• set_created: how you made a set (pasted, typed or the sample) and its number of cards.
• paste_skipped: the number of pasted lines that were not cards.
• heard_from: your answer to “Where did you hear about Terminus?”, if you give one.
• widget_guide_done: whether you added the Lock Screen widget.
• widget_answer: “good” or “again”, for each answer on the widget.
• session_done: the number of cards right and again in a finished review.
• goal_met: you met your daily goal.
• goal_chosen: the daily goal you picked in setup, as a number of cards.
• reminders_chosen: whether you turned reminders on in setup, and the hour you picked for them.
• test_date_set: the whole number of days from that day to your test, never the date.
• test_date_skipped: you said in setup that there is no test.
• widget_opened: you opened the app from a widget.
• ai_connected and ai_disconnected: you connected an AI, or disconnected it.
• ai_cards_added: the number of cards an AI added, and the AI’s name, never the text.
• share_cards_added: the number of cards you added from the Share sheet, never the text.
• $screen: the name of each screen you open: Today, Sets, Set, Set editor, Review, Paste list, Settings, Widget guide, Connect an AI, Remove cards, and the setup steps Onboarding: Welcome, First set, First review, Test date, Goal, Plan, Reminders, Heard from and Summary.
• Application Installed, Application Updated, Application Opened, Application Backgrounded: PostHog’s own events when the app is installed, updated, opened and closed, with the app’s version.

PostHog also keeps your setup answers with the app’s random ID, so we can compare people by answer: goal, has_test_date, days_until_test, reminders and heard_from. They are not linked to you: the app never sends your name or email address, and the random ID is not your Connect an AI account.

Each event also holds the time, a random ID that the app makes on your device, and facts about the device and the app: the device model, the iOS version, the app’s name and version, the language, the time zone, the screen size, Wi‑Fi or cellular, and whether the app is a TestFlight build. No event holds your name, your email address, the text of a card or the title of a set. PostHog’s server gets your IP address when the app sends, as every server does. The app tells PostHog not to find your location from it.

In the app: no purchases

The app is free. It sells nothing, and it sends nothing to a payment service.

In the app: feedback

If you send feedback from Settings, your mail app sends us your email address and what you write.

On this website: what we collect

• Your email address, when you join the waitlist.
• The link that brought you, which form you used, and your device type (iPhone, iPad, Android, computer or other), read from your browser.
• Your answers to the two optional questions, if you give them.
• Counts of visits and taps on the page. We count them without cookies and without keeping your IP address.
• Your country, region and city, with each visit, tap and sign-up. Cloudflare reads them from your IP address. We do not keep the IP address, your postcode or your exact location.
• If one of Meta’s ads brought you, the ad’s click id from the link.

We use it to send you one email, when you can try Terminus on your iPhone; to learn which links and places bring more people to the waitlist; and to tell Meta that one of its ads brought a sign-up.

Who helps us

• PostHog gets the app’s usage events, keeps the waitlist (your email, the link, the form, your device type, your country, region and city, and your answers) and counts visits and taps on this website. Its Data Processing Agreement lets it use the data only to give us its service.
• Cloudflare runs this website and its server, and the server and database of Connect an AI, under its Customer Data Processing Addendum.
• Meta gets one message when you join the waitlist: your email, scrambled with SHA-256 so that Meta can match it to an account but cannot read it, your browser’s name, your IP address, and the ad’s click id if an ad brought you. Meta uses it to measure its ads. Its Business Tools Terms make Meta keep the data confidential and secure, and delete your scrambled email after the match.
• The AI services you connect get what you type to them, under their own terms.

Each of them must give your data the same or equal protection as this policy. PostHog and Cloudflare can keep data in the United States.

How long we keep it

• On your device: until you delete it in the app, or delete the app.
• Connect an AI: changes wait at most 30 days; the copy of your cards lasts while you are connected; an account and all of it are deleted 180 days after your device last reached the server, or when you disconnect.
• Usage events: 1 year, the time that PostHog keeps them for us.
• Feedback emails: 1 year after our last reply.
• The waitlist: until we send the launch email, plus 30 days, or until you ask us to delete it, if that comes first.

Your choices

• In the app, Settings, Connect an AI, Disconnect and delete account deletes your account and everything the server keeps for it. The cards already on your device stay.
• In the app, Settings, About, Delete my data disconnects an AI first, then deletes every set, card and answer on your device.
• Deleting the app deletes all of its data on your device and stops all usage events. If you install it again, it makes a new random ID.
• The launch email has a link to leave the waitlist.
• To withdraw your consent, or to see or delete what we or the services above hold about you, write to us at contact+terminus@skailex.com. We answer within 30 days.

Children

Terminus is not for children under 13, and we do not knowingly collect data from them. If you think that a child under 13 gave us data, write to us and we delete it.

Changes

When this policy changes, we change it on this page and change the date at the top.

Contact

Serhii Kucherenko, Vancouver, British Columbia, Canada. Email: contact+terminus@skailex.com.