About Plain Chess
Plain Chess is published by Cerebra Enterprises LLC ("we", "us", or "our"). You do not need a Plain Chess account. Games against our rivals or a friend on the same iPhone, puzzles, hints, game reviews and opening lessons work offline. AI Coach, purchases, games with people on other devices, usage statistics, app settings, notices, the natural voices’ one-time download and optional feedback use an internet connection. Any network request makes technical details such as your IP address visible to the service that receives it.
On your iPhone
Plain Chess keeps your game in progress, settings, rival records, puzzle progress, practice plan, onboarding choices and AI Coach replies on your iPhone. Onboarding choices can include your chess experience, goals, preferred way to play, practice days and time, and your personal practice commitment. These choices help the app tailor your experience.
The free plan’s daily counters, the install ID described under Usage statistics, and your coach account token are kept in the iPhone’s Keychain, so reinstalling the app does not reset them. iOS can keep Keychain items after the app is removed.
To recover an interrupted AI answer, the app keeps the exact pending question, chess context, request identifier, and original Apple-signed purchase proof in protected local storage excluded from backups until the request is resolved. A completed answer is saved on your device before the app confirms delivery. Unread answers are kept, along with up to 30 read answers. Removing the app deletes this local data, apart from the Keychain items above.
Your game history and iCloud
Plain Chess saves every game you finish: the date, the moves, the result, how long it took, your accuracy, the moments to learn from and the coach’s notes, and for a game against a person, that player’s Game Center name and player ID. When you are signed in to iCloud, these games are stored in your private iCloud database through Apple’s CloudKit, so they appear on your other devices. Only you can see your private iCloud data; we cannot read it. Without iCloud, your games stay on this iPhone.
Plain Chess also uses iCloud key-value storage to keep your coach account token, and whether you have already seen the founding thank-you, the same on your devices. You can remove Plain Chess data from iCloud in your iPhone’s iCloud settings. Apple handles iCloud data under its own privacy policy.
Usage statistics and crash reports
To see which features people use and to fix problems, Plain Chess can send usage statistics and crash reports to our service on Cloudflare. Usage statistics go under a random install ID that the app creates and keeps in the Keychain. It is not an advertising ID, and it is not tied to your name, your Apple Account, your coach account token or your purchase records with us.
Usage statistics are events such as opening the app, starting and finishing a game (the mode, the rival, the result and the number of moves), opening a puzzle, using a hint, opening a review, seeing the membership screen, and inviting a friend. They also include purchase history: your plan type (free, member, family, Lifetime or original buyer) comes with every event, and starting a free trial or buying a membership, Lifetime or an answer pack is recorded with the plan or product, not the price. We use this to understand which features and plans people choose. Each event also carries its time, the app version and, while we are testing two versions of something, the test group. Usage statistics never include your moves, positions, questions, names or anything you type.
Crash and hang reports come from Apple’s MetricKit. They describe the code the app was running when it crashed or froze, with technical details such as the device model and the iOS and app versions. They are sent without the install ID.
Sharing is on by default, except for App Store accounts in the European Union, the European Economic Area, the United Kingdom, and Switzerland, where it stays off unless you turn it on. You can turn it off or on at any time in the app under Settings, Privacy, Share usage statistics. When you turn it off, the app stops sending, asks our service to delete the events it sent under your install ID, and forgets that ID, so anything sent if you turn sharing on again cannot be connected to what came before.
Our service stores the install ID only as a one-way hash, and it does not store IP addresses; to limit abuse, it counts requests under a daily salted hash of the address. Events and crash reports are deleted after 90 days. Daily totals, such as how many people played on a day, contain no install IDs and are kept.
App settings from our service
Plain Chess checks our service on Cloudflare for its current settings, such as the free plan’s limits and which features are on. That request carries no identifier. When we try two versions of something, such as the headline on the membership screen, your iPhone uses the install ID to work out which version you see; our service is not told.
Games with other people
Play a friend and Quick Match use Apple’s Game Center, and Plain Chess asks you to sign in to Game Center only when you open them. Game Center shows the people you play your Game Center name and picture, and passes your moves, draw offers, resignations and the six preset reactions between your devices. There is no chat. Play a friend lists only people you have already played in Plain Chess and, if you allow it, your Game Center friends; it never lists other Game Center players. Plain Chess asks to see your Game Center friends only when you tap Show my friends, and you can say no and still invite anyone through Apple’s invite screen or Messages. Your friends list is used on your iPhone so you can invite them; it is not sent to us. To reach people you have already played, Plain Chess looks them up in Game Center’s recent players on your iPhone and keeps no one else. Our servers do not take part in these games and do not receive your Game Center details. Plain Chess keeps the other player’s Game Center name and player ID with the game in your history, as described above. Apple handles Game Center data under its own privacy policy. If you share usage statistics, they count invitations and Quick Match results without any player IDs.
Voices and asking out loud
The voice coach and rival voices are made on your iPhone. With iOS 18 or later on an iPhone 12 or newer, turning voices on downloads the natural voices once, about 170 MB, from Apple’s App Store servers, the same way the app itself is delivered, not from our servers. Apple handles that download under its own privacy policy. Other iPhones use the voices built into iOS. Either way, the voices are made on your iPhone, and nothing spoken or synthesized leaves it.
When you ask the coach out loud, Plain Chess uses Apple’s speech recognition on your iPhone only, so your voice never leaves it. Where on-device recognition is not available, asking out loud is unavailable rather than sent to a server. The app asks for microphone and speech recognition access the first time and listens only while you are asking a question. The words it hears are sent as an AI Coach question, just like a typed one.
AI Coach
Before your first AI Coach question, the app explains what will be sent and asks for your agreement. When you ask, your question and relevant chess context are sent to our backend on Cloudflare and then to our AI provider, OpenAI, to write the reply. Context can include the board position, move history, legal moves, a suggested move, what the app noticed in the position (such as a threat or a pinned piece), whose turn it is, and the game mode. Questions you ask out loud are turned into text on your iPhone first. Do not include personal or sensitive information in your questions. AI answers can be mistaken.
Purchases and AI Coach answers
Apple processes memberships, Lifetime and answer packs through the App Store. We do not receive your full payment card number. To unlock your plan and keep count of your AI Coach answers, the app and our billing service on Cloudflare process Apple-signed purchase information, including product and transaction identifiers, the original transaction identifier, purchase and expiration dates, whether a purchase is a free trial or shared by your family, and verification status.
Plain Chess also creates a random coach account token, kept in your Keychain and iCloud key-value storage. It goes to Apple with each purchase, as Apple’s app account token, and to our billing service with your AI Coach requests, so your answer packs and any founding thank-you answers follow you to your other devices without an account. Our billing service keeps your answer balances under that token and your verified purchases. For a family membership, it uses the purchase information Apple provides for the shared membership to keep the family’s monthly answers together.
To give founding members their thank-you, the app reads your purchase history from Apple on your iPhone. For a founding yearly member, it sends the Apple-signed purchase to our billing service, which records that the thank-you answers were added for it, so they are added only once.
AI requests and replies can be associated with your verified purchase and coach account token. The billing service keeps completed replies for recovery and delivery confirmation, for up to seven days from the original request. It retains request identifiers and one-way request fingerprints to prevent duplicate processing, without a fixed deletion date. Its database does not separately save the original request payload or signed purchase proof. A reply may quote your question or chess context. The app also keeps purchase and answer information locally.
Notifications
If you allow notifications, Plain Chess schedules a reminder on your iPhone two days before a free trial ends. Game Center can tell you when it is your move in a game with a friend. We do not send notifications from our servers.
Optional onboarding feedback
If you choose to share your onboarding answers, we send your selections, a random installation identifier, app version, and submission time to our service hosted on Cloudflare. The answers help us understand what players want and improve Plain Chess. We do not ask for your name or email in this flow. The identifier is pseudonymous: it distinguishes submissions from your installation without identifying you by name. It is separate from the install ID used for usage statistics. Sharing is optional and is not required to subscribe or play. You can turn sharing off and delete your shared answers in the app. Shared answers are deleted within 365 days of their latest update, or sooner when you request deletion. Your local preferences can remain on your device after you delete shared answers.
Feedback, support, and app notices
If you send feedback or contact support, we receive what you choose to share, which may include your email, selected topics, note, app and iOS version, device details, and technical information needed to handle the request. Please leave sensitive information out of feedback. The app can fetch notices and update messages from our service using its app version.
Ad measurement with Meta
Plain Chess uses Meta’s software development kit to learn whether our ads on Facebook and Instagram bring new players. When ad measurement is on, the app tells Meta Platforms, Inc. when it is installed or opened, when a new membership or free trial starts, and when a free trial becomes a paid membership, including the plan, price, and currency. These reports include technical details such as the app version, device model, operating system, language, time zone, and an identifier the app generates, and Meta can see the IP address of the request. Plain Chess does not collect your device’s advertising identifier, does not ask to track you, and does not send your games, AI Coach questions, or onboarding answers to Meta. Meta processes this information to report on and deliver our ads, as described in Meta’s Privacy Policy: https://www.facebook.com/privacy/policy. Ad measurement is on by default, except for App Store accounts in the European Union, the European Economic Area, the United Kingdom, and Switzerland, where it stays off unless you turn it on. You can turn it off or on at any time in the app under Settings, Privacy, Ad measurement.
How we use information
We use this information to run the app, keep your games and answers in step across your devices, answer AI Coach questions, deliver purchases, understand which features and plans people use, fix crashes, measure which of our ads bring new players, prevent abuse, troubleshoot problems, respond to support, and improve the experience. We do not serve third-party ads, sell personal information, or build advertising profiles from your games or questions.
Providers and retention
Apple (purchases, iCloud, Game Center and the natural voices’ download), Cloudflare (our services), OpenAI (AI Coach), Meta (for ad measurement, when it is on), and any feedback delivery provider process the information needed for their role. Provider handling and retention are also governed by their applicable terms. Local game data and preferences remain until cleared or the app is removed. Games in your iCloud remain until you remove them from iCloud. Usage statistics and crash reports are deleted after 90 days, and daily totals without install IDs are kept. Shared onboarding answers follow the 365-day limit described above. Purchase and answer records may be kept as needed to honor access, prevent duplicate answers, handle refunds and disputes, and meet legal requirements. AI request data, support messages, and technical logs may be retained as reasonably necessary to operate, secure, support, and troubleshoot the service. We do not promise that removing the app deletes records already processed by a provider.
Your choices
You can play without AI Coach, decline to share onboarding answers, delete shared onboarding answers, and turn usage statistics and ad measurement off in the app under Settings, Privacy. You can sign out of iCloud or Game Center, and turn off microphone, speech recognition and notification access in your iPhone’s Settings. To ask about other information, access, correction, or deletion, email corporate@cerebraenterprises.com. We may need to verify your request and may retain records where required for legal, security, or purchase obligations. We do not require you to send payment card details.
Children
Plain Chess does not ask children to provide personal information. Games with other people follow the Game Center and Screen Time settings a parent or guardian chooses. If you believe a child has sent us personal information, contact us so we can review and address it.
Changes and contact
We will update the effective date when this policy changes. Cerebra Enterprises LLC, 5000 Thayer Center Ste C, Oakland, MD 21550. Email: corporate@cerebraenterprises.com.