Privacy Policy

Flippy - Page Flip PDF Reader · Effective July 18, 2026

Overview

Flippy is a PDF reader available on Android and iOS. Your privacy matters to us. This policy explains what data Flippy accesses, how it is used, and your choices.

Data Stored on Your Device

Flippy stores your library and everything you create locally on your device. This data never leaves your device unless you explicitly enable Cloud Sync (a premium feature). The AI features described further down are the exception: when you use one, the specific text you asked about is sent away to be processed, as explained in those sections.

• PDF files you import into the app
• Bookmarks, highlights, and annotations you create
• Reading progress (current page, reading history)
• App preferences (theme, reading settings, tags)
• Drawings made with the draw tool
• Your AI conversations — the questions you ask and the answers you get back are saved on your device so you can come back to them later, kept separately for each PDF. They are never uploaded, and they are deliberately not included in Cloud Sync. You can erase a PDF's conversation at any time with the "Clear chat" button in the AI panel.
• Downloaded read-aloud audio — if you choose to download a chapter for offline listening, the generated audio is saved in the app's private storage on your device and can be deleted at any time

This data is stored in your device's local storage and is not accessible to us or any third party.

Cloud Sync (Premium Feature)

If you choose to enable Cloud Sync, the following applies:

• Authentication: You sign in with your Google account via Google Sign-In. We receive your name, email address, and profile photo to display in the app. We do not store your Google password.
• Data synced: Bookmarks, highlights, reading progress, tags, and reading statistics are stored in Google Firebase Firestore, associated with your Google account.
• PDF files are never uploaded. Only your reading data (bookmarks, progress, etc.) is synced.
• You can delete your cloud data at any time from the app's settings.

AI Read-Aloud (Premium Feature)

Flippy offers text-to-speech powered by OpenAI's Text-to-Speech API.

• When you use this feature, the text of the page being read is sent to OpenAI's servers to generate audio. So that playback does not pause between pages, the text of the next page or two may be sent slightly ahead of when you reach it. If you ask Flippy to read an AI answer out loud, that answer text is sent as well.
• No PDF files are uploaded. Only extracted text is transmitted.
• OpenAI processes the text and returns audio. OpenAI's use of this data is governed by OpenAI's API Data Usage Policies. Per their policy, data sent via the API is not used to train their models.

AI Q&A, Summaries, and Study Tools (Premium Feature)

Flippy uses Anthropic's Claude API to answer questions about your PDFs, generate summaries, and create study materials (flashcards and quizzes) from chapters you choose.

• When you use these features, the text content of your PDF (the most relevant pages for your question, or the chapter you selected) is sent to Anthropic's Claude API along with your question.
• To work out which pages are the most relevant, Flippy may first send your document's table of contents together with a short one-line extract from each page. This step covers more of your document than the answer step, but it is used only to pick the right pages to read closely.
• This data is processed to generate a response and is not stored by Flippy.
• Anthropic's use of this data is governed by Anthropic's Commercial Terms. Per their policy, data sent via the API is not used to train their models.

Speak-to-PDF Voice Questions (Premium Feature)

Flippy lets you ask questions about your PDF out loud. This feature uses your device's microphone.

• The microphone is only active while you are recording a question (after you press the microphone button). Flippy never listens in the background.
• Flippy tries to transcribe your speech on your own device first, using the speech recognition built into Android or iOS. When that succeeds, your recording never leaves your device — only the resulting text is used, and the recording is deleted straight afterwards. On most modern Android devices this is what happens.
• If on-device transcription is unavailable or produces no result, your voice recording is sent via our backend to OpenAI's transcription API (Whisper) instead. On iPhone and iPad this is currently the usual path, because Apple's on-device transcription does not reliably return a result for recordings made this way. The recording is used only to produce the transcript and is not stored by Flippy or our backend beyond the lifetime of that request.
• The transcribed question is then handled exactly like a typed AI question (see AI Q&A above), and the spoken answer is generated with OpenAI's Text-to-Speech.
• OpenAI's handling of this audio is governed by OpenAI's API Data Usage Policies. Per their policy, data sent via the API is not used to train their models.

AI Explain (Premium Feature)

When you highlight a word or phrase in a PDF and tap "Explain," Flippy generates a short, even-handed explanation of that term.

• The highlighted text and surrounding page content are sent to Anthropic's Claude API (via our backend) to generate the explanation, the same way AI Q&A works. This data is not stored by Flippy and is not used to train Anthropic's models.
• To show relevant pictures, the highlighted term (or a short related search phrase the AI suggests based on it) is sent to Wikipedia / Wikimedia to look up public images and their descriptions, which are shown as captions. This is a standard public search request; no account, login, or personal data is involved.

In-App Purchases

Flippy offers optional premium subscriptions. All purchases are processed by Apple (App Store) or Google (Google Play). We do not collect or store any payment information. Purchase management and billing are handled entirely by the respective platform.

Analytics and Advertising

There are no ads inside Flippy. We do not display ads, sell your data, or include any third-party advertising or analytics SDKs (no Meta/Facebook SDK, no Google Analytics, no crash reporting SDKs).

Flippy uses a small backend service we operate (a Cloudflare Worker) to route AI Q&A and Read-Aloud requests to their respective providers (Anthropic and OpenAI). This proxy lets us keep our API keys server-side so they aren't extractable from the app. The backend receives:

• An anonymous install token — a random ID created the first time the app contacts our backend. It is stored on your device, and our backend keeps a record of it alongside the date it was created, your platform, the app version, and the IP address it was created from. It is used to apply rate limits per install so a single device can't run up unexpected charges, and to count unique installs in the anonymous event counters described below. It is not linked to your name, email, or any account, and reinstalling the app creates a brand-new token.
• The text of your AI question (or highlighted term) and the PDF content you're asking about (only for AI Q&A, summary, Explain, and study-tool requests; only for as long as it takes to forward the request).
• The page text you've asked Flippy to read aloud (only for Read-Aloud requests).
• Your voice recording when you ask a question with Speak-to-PDF and it could not be transcribed on your device (only to forward it for transcription; see the Speak-to-PDF section above).
• Your App Store or Google Play purchase receipt when the app verifies a premium subscription. The receipt contains no name, email, or payment details; the verification result is cached for up to 24 hours.
• Your IP address, as is standard with any HTTPS request. It is recorded once alongside your install token when that token is first created, and it appears in our backend's short-term request logs. Cloudflare may also retain it in standard request logs (typically days, not months).

The backend does not store the contents of your questions or PDF pages beyond the lifetime of each request. It does not receive bookmarks, highlights, notes, reading history, or any data that identifies you.

The backend also keeps small, anonymous daily counters of certain in-app events so we can understand how Flippy is used, improve the app, and detect abuse of free features. Examples: the app being opened (counted at most once per day per install, so we can see how many devices actively use Flippy), a PDF being imported, the upgrade screen being viewed, a purchase completing, or a monthly usage limit being reached. Only the name of the event is counted — never the content of your documents, questions, notes, or anything that identifies you — and the counters roll off after 90 days.

Reading reminders (daily notifications) are generated and scheduled entirely on your device. The name of your last-read PDF and your monthly listening totals are stored locally to personalize them and never leave your device. You can turn reminders off anytime in Settings.

Third-Party Services

Flippy integrates with the following third-party services. Except where noted, each is contacted only when you explicitly use the corresponding feature:

• Google Sign-In — for Cloud Sync authentication
• Google Firebase / Firestore — for cloud data storage
• OpenAI Text-to-Speech and Whisper transcription APIs — for AI Read-Aloud, for speaking AI answers out loud, and for transcribing Speak-to-PDF voice questions that your device could not transcribe locally (routed via our backend; see Analytics section above)
• Anthropic Claude API — for AI Q&A, summaries, AI Explain, and study tools (routed via our backend; see Analytics section above)
• dictionaryapi.dev — for in-app word definitions (only the selected word is sent; no account or API key required)
• Wikipedia / Wikimedia — for the images and captions shown in AI Explain (only the highlighted term or a related search phrase is sent; no account or API key required)
• Cloudflare Workers — our own backend proxy that holds OpenAI/Anthropic credentials and applies rate limiting
• cdnjs (a public Cloudflare CDN) — Flippy loads the open-source library it uses to draw PDF pages from this public CDN. This happens every time the app starts, not only when you use a particular feature. Only the ordinary information carried by any web request is involved, such as your IP address; none of your documents, questions, or reading data is sent.

Each service is subject to its own privacy policy. Apart from the CDN noted above, no data is shared with these services unless you actively use the corresponding feature.

Children's Privacy

Flippy is not directed at children under the age of 13. We do not knowingly collect personal information from children.

Data Deletion

You can delete all your data at any time:

• Local data: Uninstall the app or clear app data from your device settings.
• AI conversations: Use "Clear chat" in the AI panel to erase the conversation for a single PDF, or uninstall the app to remove all of them. They are only ever stored on your device.
• Cloud data: Use the "Delete Account & Data" option in Flippy's settings. This deletes the reading data we hold for you in Firestore. The sign-in record itself may remain with our authentication provider — email us at the address below and we will remove it for you.

Changes to This Policy

We may update this privacy policy from time to time. Changes will be posted on this page with an updated effective date.

Contact Us

If you have questions about this privacy policy or your data, contact us at:

flippypdf@gmail.com