Privacy Policy for Lemma

Last updated: October 9, 2026 · Effective: October 9, 2026

This Privacy Policy describes how Lemma ("We", "Us", "Our"), made by Laxmi Solutions, handles your information when you use the Lemma app. In short: your documents stay on your phone. Lemma has no account system, no servers of its own that receive your documents, no advertising and no analytics.

1. What is Lemma?

Lemma is a LaTeX editor for Android. You write documents, and Lemma compiles them to PDF on your device with a built-in TeX engine. Optional features let you sync projects with Git or Google Drive, and Lemma Pro adds Snap math (turning a photo or drawing of a formula into LaTeX) and conversion to Typst.

2. Information We Collect

We do not collect personal information. Lemma does not ask you to sign up, and it contains no analytics, advertising or crash-reporting SDKs. The sections below explain what stays on your device and the network connections Lemma makes on your behalf.

2.1 Your Projects and Settings (On Your Device)

Your projects (.tex, .bib, images and other files), compiled PDFs and settings are stored in Lemma's private storage on your phone. We never receive them. Uninstalling the app or clearing its data removes them, unless they are kept in an Android backup (section 2.8) or synced by you (sections 2.4 and 2.5).

2.2 Compiling and TeX Packages

Documents are compiled entirely on your device. The first time a document uses a TeX package (for example amsmath), Lemma downloads that package's files from a TeX package server (the Tectonic project's distribution server, or a mirror operated by us) and keeps them on your device so later compiles work offline. These requests contain only the names of the package files needed; your document's content is never sent. Like any web server, the package server can see your IP address and the time of the request.

You can see and clear downloaded packages in Settings → Downloads.

2.3 Downloads Through Google Play

To keep the app small, the offline compiler and the Snap math feature are delivered by Google Play as optional downloads, and the app may check Google Play for updates. These downloads are handled by Google Play under Google's Privacy Policy.

2.4 Git (Optional)

If you clone a repository or connect a project to Git, Lemma talks directly to the Git host you choose (for example GitHub or GitLab) over HTTPS. If you enter a username and access token, they are stored only on your device, encrypted with a key held in the Android Keystore, and are sent only to that Git host. Commits you push include the author name you set and contain your project files, as with any Git client. You can remove saved credentials in Settings → Sync → Git.

2.5 Google Drive (Optional)

If you turn on Google Drive sync for a project, Lemma asks for the drive.file permission, which lets the app see and manage only the files and folders it creates in your Drive, not your other Drive files. Project files are copied directly between your device and Google Drive; they never pass through our servers. Lemma stores the email address of the connected Google account on your device so it can show which account is connected.

Lemma's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. We do not use Google Drive data for advertising, do not sell it, and do not use it to train AI models.

You can turn sync off per project in Share & sync, and revoke access at myaccount.google.com/permissions.

2.6 Snap Math and the Document Scanner (Lemma Pro)

Formula recognition runs on your device with a bundled machine-learning model; images are not uploaded. The camera scanner is Google's ML Kit document scanner, provided by Google Play services, which processes the scan on your device and hands Lemma only the resulting image. Lemma does not request the camera permission itself.

2.7 Purchases

Lemma Pro is a one-time purchase through Google Play Billing. Google handles payment; we never receive your card or payment details. The app asks Google Play whether Lemma Pro is owned by your Google account and remembers the answer on your device so Pro features work offline.

2.8 Android Backup

If Android backup is enabled on your device, Android may back up your projects and settings to your Google account, under Google's terms. Downloaded TeX packages, the Snap model, and your Git and Drive credentials are excluded from backups.

2.9 Ratings

After you have used Lemma for a while, the app may ask Google Play to show its in-app rating prompt. Your rating and review go to Google Play; we do not receive them through the app.

3. Permissions

Internet and network state — to download TeX packages, Git and Drive sync, Google Play downloads and purchases, and to download the offline compiler only on Wi-Fi.

Lemma opens files and folders only through Android's file picker, so it can read only what you choose to import.

4. How We Share Information

We do not sell, rent or share personal information, because we do not collect it. The only services Lemma communicates with are the ones you use: Google Play (downloads, updates, purchases, ratings), Google Drive (if you enable it), your Git host (if you use Git), and the TeX package server (for package files).

5. Data Retention and Deletion

Everything Lemma stores is on your device. You can delete a project in the app, clear downloaded packages in Settings, remove Git credentials in Settings, or clear the app's data or uninstall it to remove everything. Data you pushed to a Git host or synced to Google Drive stays there until you delete it in that service.

6. Security

Network connections use HTTPS. Git tokens are encrypted with a key held in the Android Keystore. Projects are kept in the app's private storage, which other apps cannot read. No method of storage or transmission is 100% secure, but we design Lemma to keep your data on your device.

7. Children

Lemma is a general-purpose writing tool and is not directed to children under 13 (or the minimum age in your country). It does not knowingly collect personal data from anyone.

8. Your Rights

Because we do not hold your personal data, there is nothing for us to access, correct or delete on our side. For data held by Google (Play, Drive, backups) or your Git host, please use those services' controls. If you have any question, contact us below.

9. Changes to This Policy

We may update this Policy from time to time. We will revise the "Last updated" date above and, for material changes, provide notice in the app. Previous versions remain available on this page.

10. Contact

Laxmi Solutions — laxmi.solutions.2025@gmail.com