Spine — Privacy Policy
Effective 10 September 2026
Spine collects nothing. There is no account, no sign-in, no cloud sync, no advertising and no analytics. We do not operate a server that receives your data, so there is nothing for us to collect, sell, or lose.
What stays on your device
Everything Spine makes lives in the app's own storage on your phone:
- the books you add — Spine keeps a copy, and your original file is never touched
- your reading position, highlights and notes
- your settings: typeface, size, theme, voice
- any pronunciations you teach it
None of it leaves your device unless you tap Export and choose where to save it.
When Spine uses the network
Spine asks for internet permission for exactly three things, and you start all three:
- Browsing and downloading from an OPDS catalogue — Project Gutenberg, Standard Ebooks, or your own Calibre content server — when you open Sources and tap.
- Downloading a voice, when you choose one in Settings › Voice. The voice file comes from a public repository; nothing about you is sent with the request.
- Look Up, which hands the selected word to another app on your device that you pick. Spine does not send it anywhere itself.
Outside those, Spine does not connect. It does not call home at launch, check for updates, or send crash reports.
One detail worth stating plainly: a Calibre server on your own network is normally reached over plain HTTP, because that is how Calibre publishes it. That traffic is unencrypted on your local network. Catalogues on the internet are reached over HTTPS.
Reading aloud
Spine reads with voices on your device. Many phones also offer voices that synthesise on a server; Spine actively refuses those and uses only on-device voices — because reading a book aloud through a network voice means sending the text of that book to someone else's computer, sentence by sentence.
Payment
Spine is sold once, through Google Play. Google handles the payment. We never see your card, your address, or your identity. Google tells the app one thing: whether this account has bought it.
Google's own policies cover how they handle payment data.
Children
Spine is not directed at children under 13, and collects no data from anyone, of any age.
Deleting your data
There is nothing held on our side to request the deletion of. Uninstalling Spine removes everything it keeps on your device. You can Export your highlights and notes first if you want to take them with you.
Changes
If this policy changes, the new version appears at this address with a new effective date.