Privacy policy
Last updated: October 29, 2026. The Spanish version is the original; this is a translation.
Who we are and who this applies to
Clase Offline is an app for working in class without internet: the teacher publishes assignments, students turn in work and chat, and everything travels directly between phones over Bluetooth and Wi-Fi. It is developed by Alfredo Augusto Sánchez, a teacher in Mendoza, Argentina, who is responsible for this policy and for the data. Contact: yayoar@gmail.com.
This policy explains what data the app uses, where it is stored and who can see it. It applies to everyone who uses the app: teachers, students and their families.
What data the app uses and where it is stored
Class data is stored on the teacher's phone and on the phones of the students in that class. It travels directly from phone to phone, without internet.
| Data | Purpose | Where it is stored | Who can see it |
|---|---|---|---|
| Student's name | Know who turned in work and who gets each grade | Classroom phones | The teacher and classmates |
| Teacher's name | Let students know who publishes and grades | Classroom phones | The class |
| Assignments and their files | What the teacher asks for | Classroom phones | The class |
| Submissions (text, photos and files) | What the student turns in | The student's phone and the teachers' phones | The student and their teachers |
| Grades and comments | Feedback | The student's phone and the teachers' phones | The student and their teachers |
| Class chat messages | Talking in class | Classroom phones | The class |
| Private messages | One-to-one conversations | Both phones, end-to-end encrypted | Only the two people talking |
| Review game results | The game leaderboard | Classroom phones | The class |
| Phone model and a random number | Recognize the phone when it rejoins the class | Classroom phones | The teacher |
| Google account email | Connect to Classroom and Drive, and keep track of the teacher's AI credits | On the phone itself (for credits, see below) | No one else |
The app never sees or stores passwords, and it does not store the phone's location.
If someone reports a private message, the teacher can read only that message in order to decide what to do.
Technical data in test versions. In test versions, each phone records how the connection performed: phone model and Android version, battery, power saving, dropouts and errors. This data contains no names, messages or assignments, and only reaches the teacher's phone. It is used to improve the app. The public release does not record it.
Features that use the internet
These features only work when the phone is online: over Wi-Fi or, if the person chooses so in Settings, also over mobile data. None of them is required to use the app in class.
Google Classroom
If the teacher links a class to a Classroom course, the app retrieves the course roster (names and emails), publishes assignments there, retrieves submissions made in Classroom and posts grades. If a student links their account, their submissions are uploaded to that Classroom assignment from their own phone. Everything goes from the phone directly to Google; the data does not pass through any server of ours.
- Teacher permissions: see their courses and the students in each course, see their emails, publish assignments and post grades, and upload assignment files to a "Clase Offline" folder in their Drive.
- Student permissions: see and turn in their own assignments, and upload submission files to their Drive.
- The app can only see Drive files that it created itself. It cannot see the rest of the Drive.
Google asks for permission before these features are used for the first time. Access can be removed at any time from the Google account (Security → Third-party apps with account access).
Google Drive backup
If the person turns it on, the app stores a copy of their classes, assignments, submissions, grades and chats in their own Drive, in a hidden folder used only by this app. It is used to restore everything on a new phone and can be turned off in Settings.
Internet chat
So that messages arrive even outside class, the app uses Firebase, a Google service.
- Private messages are published end-to-end encrypted: no one but the two people talking can read them, not us and not Google.
- Group chat messages are stored with the name of their author. Reading them requires the class key, which only members receive when they join in class.
- The app signs in to Firebase anonymously: it does not ask for an email or personal data.
- Group messages stay in Firebase while the class exists. Anyone who wants them deleted can ask using the contact below.
AI-generated questions for games
Only teachers use this feature, when they tap "Generate questions". To create the questions, the app sends our server (which runs on Google Cloud / Firebase) the topic the teacher typed and, if the teacher chose an assignment, its instructions and files. The server passes them to Anthropic, the company that provides the Claude AI model, which returns the questions.
- Only the material of the assignment the teacher chose is sent. No student names, submissions, grades or messages are sent.
- Neither our server nor the app keeps a copy of the material sent: it is used to create the questions and then discarded. The generated questions are stored on the teacher's phone.
- Anthropic processes that material under its commercial terms and privacy policy (anthropic.com/legal/privacy); under those terms, it does not use it to train its models.
- We recommend not including students' personal data in the topics or files used to generate questions.
AI credits and purchases
To keep track of each teacher's AI credits, the app identifies itself to our server with the teacher's Google account (permission to see the email address only). The server checks with Google that the email is valid and stores in Firebase a code derived from the email (a hash, not the readable email), together with the number of free, used and purchased credits and the sign-up date.
Credit purchases and the subscription are handled by Google Play. Payment details are handled by Google, and the app never sees them. To credit a purchase, the server stores the Google Play purchase and order identifiers, the product and the date, so that the same purchase is never credited twice.
Transferring grades to the GEI (teachers in Mendoza only)
Clase Offline is not an official app of the Mendoza School Board or the Government of Mendoza and is not affiliated with them. The assisted transfer opens the official GEI website inside the app, like a browser: the teacher signs in with their own username and password, which the app does not read or store, and the app fills in the grade sheet with the grades the teacher entered in Clase Offline. The teacher reviews them and saves them in the GEI.
- Grades go from the phone directly to the GEI; they do not pass through our server.
- The phone keeps the GEI session (like any browser), which GEI name matches each student in the class, and how many free transfers have been used.
Google processes data from its services under its own privacy policy. Clase Offline's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements: that data is only used for the features described here, is not transferred to third parties (except as needed for those features or as required by law), is not used for advertising and is not used to train artificial intelligence models.
Who data is shared with
We do not sell data or share it for advertising. Only these providers are involved, and only for the features described:
- Google (Classroom, Drive, Firebase, Google Cloud and Google Play), for Classroom, backup, internet chat, credits and purchases.
- Anthropic, only with the material the teacher chooses for generating questions.
- The Mendoza School Board (DGE), when the teacher transfers grades to its own GEI system.
Phone permissions
| Permission | What it is used for |
|---|---|
| Nearby devices and Bluetooth | Find the class and connect phones to each other |
| Location | Required by Android to discover nearby phones over Bluetooth and Wi-Fi. The app does not store or send the location |
| Wi-Fi | Connect phones over Wi-Fi Direct, which is faster than Bluetooth |
| Camera | Scan the class QR code and take photos to turn in an assignment, only when the person chooses to |
| Notifications | Notify about assignments, submissions, grades, messages and requests to join the class |
| Internet | The features in the previous section |
| Stay active while minimized | Keep the class connected if the person switches to another app during class |
Attached files are picked by hand: the app does not scan the gallery or the phone's files. It does not read contacts either; to invite someone, the person chooses who to share the message with.
Children
The app is designed for school use, with a teacher in charge of each class. Students can only join a class with their teacher's code or QR code, and the teacher accepts each one.
Students see no ads and cannot buy anything: purchases (AI credits and the GEI subscription) are for teachers only. Students do not use AI question generation. Teachers can mute a student in the chat, remove them from the class and review reported messages.
Security
- Private messages are end-to-end encrypted.
- Joining a class requires the teacher's approval.
- A teacher can only join another teacher's class with a QR code and a key that expire when the invitation closes.
- Connections to Google, Firebase, our server and Anthropic are encrypted.
Retention and deletion
Data stays on the phones while the class exists.
- If the teacher deletes a class, it is deleted from their phone and from the phones of their students and the other teachers of the class.
- If a student leaves a class, it is deleted from their phone.
- Uninstalling the app deletes everything it had on that phone.
- The Drive backup can be deleted from Google Drive (Settings → Manage apps).
- AI credit and purchase data is kept while the teacher uses the feature. It can be deleted on request using the contact below; purchase records may be kept for as long as the law requires.
More details in How to delete your data.
Your rights and contact
You can ask to access, correct or delete your data, or ask any question about this policy, by writing to yayoar@gmail.com. If you are a minor, you can do so with your family or your teacher. In Argentina, these rights are set out in Law 25,326 on Personal Data Protection, and the supervisory authority is the Agency for Access to Public Information (Agencia de Acceso a la Información Pública).
If this policy changes, the new version is published at this same address with the date above updated. Important changes are also announced in the app.