Mark & Tally privacy policy
Mark & Tally is operated by EulerWorks LLC. Updated October 2, 2026.
Photos and counting
When you request a count or object outlines, your prepared photo and object name are sent to our backend and Google Gemini for processing. The mobile app resizes photos before sending them. Photos are selected by you from your device; they are not fetched from your Google account. Gemini analyzes the photo to return object locations and a count, or optional object outlines. We do not use Google Workspace APIs for photo processing, and we do not use Google account data to develop or train generalized models. Choose photos you are entitled to process and avoid including sensitive information you do not want sent.
A count does not automatically save your photo to your account Library. Choose Save to Library to store the photo, object name, detection marks, and later corrections on our backend. Exported files are saved or shared where you choose.
Google sign-in: access, use, storage, and sharing
Mark & Tally requests only basic Google sign-in permissions: openid, email, and profile. Google provides an identity token containing your stable Google account identifier, email address, name, and profile picture information when available. We receive the token to verify that you control the account. We do not receive your Google password and do not request permission to read Gmail, Google Drive, Google Photos, calendars, contacts, or other Google account files.
We use the verified Google account identifier to sign you in, restore your Library on another device, and link Google sign-in to an existing account when you explicitly choose to do so. Our backend stores the stable identifier, account ID, session records, and usage totals. It does not persist the Google email address, name, profile picture, or identity token as account profile data. The Google sign-in interface may display your name or profile picture directly from Google.
The Google identifier is stored in our Railway-hosted account database to operate sign-in and your shared Library. Google handles authentication, and Railway supplies infrastructure for our service. We do not send your Google sign-in token or profile information to Gemini as part of a counting request. We do not sell Google user data or share it with advertisers or data brokers. We do not use Google sign-in data to train artificial intelligence or machine-learning models.
The stored Google identifier remains until you delete your account. Signing out ends the current device session but does not delete the account or Library. You can also revoke Mark & Tally access in your Google Account connections settings; revocation does not itself delete data already stored with Mark & Tally. Use the deletion options below to request removal of that data.
Guest access, Apple sign-in, and device connection
You can count as a guest. Apple sign-in uses a stable Apple account identifier to access your account. Linking another sign-in method requires an explicit sign-in action; we do not automatically match accounts by email address.
Connection codes expire after five minutes and can be used once. Only share a code with a device you control. Sessions use a token that can remain valid for up to 30 days. Signing out revokes that device session.
Data protection
The public service uses HTTPS to protect data in transit. The backend verifies Google identity tokens against Google's signing keys and checks their issuer, intended application, expiry, and a one-use sign-in challenge. Access to your saved Library requires an authenticated account session. Mobile session tokens use platform secure storage; the web stores its session token in browser storage. Keep your devices and browser accounts secure.
We do not intentionally record sign-in tokens, provider credentials, or photo contents in counting error logs. No system can guarantee absolute security. Contact support if you believe someone has accessed your account without permission.
Storage and retention
Saved Library photos and results remain until you remove them or delete the account. Account deletion removes the backend account, sessions, saved Library photos, results, and usage records. Files you exported or saved locally are separate and must be removed from those devices yourself. Guest accounts without active sessions or saved records may be removed after 30 days.
The web workspace stores its session token and may contain older browser-only saved photos. Mobile session tokens use the platform’s secure storage. We keep usage totals and limited request information to enforce allowances, prevent abuse, and diagnose errors. Provider credentials and photo contents are not included in our counting error logs.
Service providers
Railway hosts our backend, account database, saved Library, and website. Google processes counting requests and Google sign-in; Apple processes Apple sign-in. Their services are subject to their own policies. We do not sell your photos or account information and do not include advertising or analytics tracking scripts in the current app and website.
Your choices, deletion, and questions
Use Delete account in the iPhone app’s Account settings. For other platforms, or if you cannot access the account, contact support@euler-works.com with the subject “Mark & Tally account deletion”. We will verify account ownership before processing a request. Do not send passwords or sign-in tokens.
You can choose guest access, avoid uploading a photo, remove saved Library items, sign out, export your saved results, or request account deletion. If you need access to or correction of account information, contact support. Changes to this policy will be published here with an updated date; material changes to Google data use will require notice and consent where applicable.
For questions about this policy, contact support.