ReadSense is provided by its developer, ReadSense ("we", "us"), who can be reached at support@readsense.app. This policy says what the app sends off your device, what we keep, and what we do not. There are no accounts in ReadSense. We do not ask for your name, email address or any other contact detail, and we do not know who you are.
The short version
Your books stay on your device.
When you make a lookup, the text needed to answer it is sent to our server and on to OpenAI, which writes the answer. We do not keep that text. OpenAI may keep it for a limited time to monitor for abuse.
We keep counts and costs of lookups against an anonymous identifier, so that free lookups and subscriptions work and cannot be abused.
No advertising, no tracking, no analytics software from other companies, no selling of data.
What stays on your device
The books you import and the files unpacked from them.
Your place in each book, your text size and theme, and the language you choose for explanations.
That you have seen the welcome screen and the reading tip, and that you have given the permission described below.
Answers you have already seen in the current session, which are forgotten when the app closes. ReadSense keeps no history of what you looked up.
Counts used only to decide when to show Apple's "rate this app" request. They are never sent to us.
Pronunciation is spoken by your device's own voice. Nothing is sent to produce it.
What is sent when you make a lookup
Nothing about your book leaves your device until you tap a word or select a passage. Before your first lookup the app tells you what follows and asks for your permission; if you answer "Not Now", nothing is sent.
For each lookup the app sends to our server:
The text needed to explain it: the words you selected and text around them from the same chapter (for a word, about two paragraphs before it; for a passage, up to the chapter so far, to the end of the selected paragraph). Nothing from later in the book, and not the book's title or author.
The language you chose for explanations.
Proof that the request comes from a genuine copy of the app (see "Identifiers" below).
Our server passes the text and the language to OpenAI's API, which generates the explanation, and streams the answer back to you.
We do not store this text. It is not written to our databases or our logs, and neither is the answer. Our logs record only that a lookup happened: its type, size, cost, timing and outcome.
OpenAI processes the text as our service provider. Under its API terms it does not use this content to train its models by default. It may retain content for a limited period, currently up to 30 days, to monitor for abuse, after which it is deleted unless the law requires otherwise. OpenAI's own policies describe this: https://openai.com/policies. If we change AI provider, we will update this policy before your text is sent to the new one.
Identifiers
An installation identifier. The app creates a random identifier on first use and keeps it in your device's Keychain. It identifies an installation of the app, not a person. It is sent with each lookup so our server can count that installation's free lookups.
App Attest. Apple's App Attest service lets our server check that a request comes from a genuine copy of ReadSense on a real Apple device. It involves a cryptographic key made on your device and a certificate from Apple. It does not tell us who you are or which device you have.
DeviceCheck. So that deleting and reinstalling the app does not grant a new set of free lookups, we use Apple's DeviceCheck service, which lets us store two yes-or-no values per device with Apple. They record only whether a trial has been started on the device. We cannot identify the device from them.
Your subscription. If you subscribe, the app sends our server the purchase record signed by Apple. From it we keep the subscription's transaction identifier, the plan, and its dates and status, so that your subscription works on your devices and ends when Apple says it has. Apple also notifies our server of renewals, refunds and cancellations. We never receive your name, your Apple Account, your email address or your payment details: Apple handles payment.
What we keep, and for how long
For each installation and each subscription: how many lookups have been made, what they have cost us, and what is needed to enforce limits. Kept while the installation or subscription is in use.
A usage record for each lookup: the time, the type of lookup, the explanation language, the model used, sizes, cost, timing and outcome, with a scrambled (salted and hashed) form of the installation or subscription identifier. No book text, selection or answer. Deleted after 90 days.
A list of subscriptions we have been told of: the transaction identifier, plan status and dates. Kept while the subscription is live and for our accounting afterwards.
Your IP address is seen by our hosting provider, Cloudflare, as with any internet service, and is used briefly to limit floods of requests. We do not store it with your usage.
What we use it for
Only to provide the service: to answer lookups, to count free lookups and apply fair use, to check and honour subscriptions, to prevent abuse and fraud, and to see in aggregate how the service is performing (how many lookups, how fast, how costly). We do not build profiles, we do not advertise, and we do not sell or share data for advertising. We do not track you across other companies' apps or websites.
Who else is involved
OpenAI generates the explanations (United States).
Cloudflare hosts our server and its databases, and delivers our alerts by email to us.
Apple provides the App Store, purchases, App Attest and DeviceCheck.
These providers may process data in the United States and other countries. We share nothing with anyone else, unless the law requires it.
Your choices and rights
You can read without ever making a lookup; then nothing about your books is sent.
Deleting the app removes your books and settings from the device. The installation identifier in the Keychain may remain on the device, so that reinstalling does not start a new trial.
Depending on where you live, you may have rights to access, correct, delete or object to the use of personal data about you. Because we hold no name or contact detail, we can usually act on a request only if you can tell us the identifier concerned; write to us and we will help you find it and will delete the counts and records kept against it. You also have the right to complain to your local data protection authority.
Where the law requires a legal basis: we process the data above because it is necessary to provide the service you ask for, and because we have a legitimate interest in preventing abuse and keeping the service running.
Children
ReadSense is not directed to children under 13 (or the age your country sets), and we do not knowingly collect personal data from them.
Security
All communication between the app and our server is encrypted. Access to the server and its records is limited to us. No system is perfectly secure; the surest protection here is that we do not hold your books, your identity or your lookups' text.
Changes
We will update this policy when what the app does changes. The date at the top shows the latest version, and a change to what is sent or to who processes it will be shown in the app before it takes effect.