Privacy policy — Paper Mentor

Last updated: 16 October 2026. Contact: sid@papermentor.xyz.

Paper Mentor writes you a short book from the ideas of real, published books. This policy describes exactly what leaves your phone and what does not. It is written to be checkable against the app: everything here is visible in the app under How it works and Settings, and the payload list appears before you are asked to type anything.

There is no account

The app never asks for an email, a name, a phone number or a password, and it has no sign-in. Nothing you do in it is tied to an identity, because there is no identity to tie it to.

What leaves your phone

Up to five things, and only when you ask for a book to be written:

1. Up to three topic words you chose from a fixed list — sent to Open Library, a free public catalogue run by the Internet Archive, as a book search.
2. One optional sentence, if you choose to write one. It is used to write your chapters and for nothing else. Skipping it is fully supported and the app works the same way without it.
3. A chapter's own title and the titles of the books it draws on, so the next chapter can be written.
4. A random string generated on your device at install, so that one phone cannot use up the writing service's capacity. It is not an identifier for you, it is not joined to anything, and you can replace it at any time in Settings → Install id → Replace.
5. If you subscribe, the purchase token Google Play gives the app — a long random string that stands for your subscription. The app sends it with each chapter request so the server can ask Google whether the subscription is active and which plan it is. It carries no name, email or card details; the server never sees those.

Items 2 and 3 are sent to Anthropic, whose model Claude writes the prose, by way of this app's own small server. Item 1 goes to Open Library. Nothing else is sent anywhere — with one exception, which only happens if you choose it.

If you report a chapter

Every chapter has a Report this chapter link at its end. If you use it, the app sends us what the report sheet lists before you tap Send: the reason you picked, a note if you write one, the chapter's title and number, the book's title, and the chapter's text — which may quote back words you gave the press.

It does not send your install id, your network address, your answers, your marks or the lines you kept, so a report cannot be tied back to your phone. That also means we cannot reply to one. Reports are read by the people who make this app and used to improve what the press writes. We keep the most recent 500, and all of them are deleted automatically 180 days after the last one arrives.

What never leaves your phone

• Your marks and verdicts on chapters, your notes, and any lines you keep.
• Your books themselves, once written.
• Your contacts, location, photos, calendar, microphone, camera, or anything about your other apps — none of which the app requests.
• Analytics, usage statistics, crash reports, or an advertising identifier. The app contains no analytics or advertising software of any kind.

What is stored, and where

On your phone: everything — your answers, your books, your marks, your settings. This is the only copy. The app opts out of Android's automatic cloud backup, so your books are not copied into your Google account either; the export described below is the backup, and it is one you control.

On the app's server: none of your text. It holds no database and keeps no record of what you send. It receives a request, asks the model for prose, streams the prose back, and forgets it.

What it does keep is counters, never text:

• Hourly counters, so that a single phone or a single network cannot use up the writing service for everyone. They expire after an hour.
• Whether this install has had its free chapter, and how many free chapters have been written from one network address today. The daily count expires after two days; the free-chapter mark is kept so the first chapter stays free once per install.
• If you subscribe, how many chapters you have used this month, and for ten minutes Google's answer about your subscription (the plan, whether it is active, and its start and renewal dates). The monthly count expires after forty days.

Every counter is keyed by a salted one-way hash — of the install id, the network address, or the purchase token. None of those is stored as itself.

At Anthropic: the text sent for writing is handled under Anthropic's privacy policy and its commercial terms, which at the time of writing do not use API inputs to train models.

At Open Library: a book search, handled under the Internet Archive's privacy policy.

Deleting your data

Uninstalling the app deletes everything it holds, immediately and permanently — there is no server copy to delete and no request to make of us. Because that is irreversible, the app offers an export (in each book's colophon) that writes a file you control; you can restore it later under How it works → I have a backup.

There is also Settings → Delete every book on this device, which does the same thing without removing the app.

Diagnostics

The app keeps the last six errors on the device, so that if something breaks you can see what it was. They are shown in Settings → When something went wrong, they record only what the app was doing and what the error said — never the text of your book or what you wrote — and they are never uploaded. You can clear them there, and they leave the phone only if you choose to send them.

Notifications

If you allow it, the app sets one local reminder a day at a time you choose. It is scheduled by your phone, not by a server; nothing is sent to us to make it happen, and turning it off in Settings stops it.

Children

The app is not directed at children and asks for no age information. It writes about adult concerns — work, decisions, endings — and if a reader's own words suggest they are in crisis, the app abandons the planned chapter and points them at real help rather than continuing.

Payment

The first chapter is free. After that, chapters need a subscription — monthly or annual, on one of two plans — bought and billed through Google Play. Google handles the payment under the Google privacy policy; this app never receives your card or bank details, your name or your email.

What the app does receive is the purchase token described above, which the server checks with Google's Play Developer API to see whether the subscription is active and which plan it is. You can cancel at any time in Google Play; the plan stays active until the end of the period you have paid for. The app shows no advertising.

Changes

If this policy changes in a way that affects what leaves your phone, the change will appear in the app on the same screens as the list above, not only here.