Privacy Policy for 3D Printing Studio

1. Who We Are

3D Printing Studio ("the app") is developed and published by NETSTED (Netsted Infotech), Trichy, Tamil Nadu, India. In this policy, "we" and "us" refer to NETSTED, and "you" refers to the person using the app.

2. Information Stored on Your Device

The app is a business tool for 3D-printing makers. It stores the following in a database on your device:

• Customer records you enter: name, phone number (with country code), email address, postal address, and any notes you add
• Order records: order numbers, customer name and contact, line items, prices, discounts, advances, balances, payment mode, payment and refund status, and the order's history log
• Filament inventory: brands, types, colours, weights, spool counts, cost and sell rates, stock purchases and stock movements
• Products: your catalogue of finished goods
• Reminders: the title, body and scheduled time of reminders you create
• Preferences: currency symbol, operator name, order-number prefix, dark-mode setting and feature choices

We do NOT collect, and the app does not contain:

• Any analytics, telemetry, crash-reporting or tracking SDK
• Advertising, ad IDs or advertising SDKs
• Device identifiers
• Location data
• Any server operated by us that receives your data — we have none

The app has an "Analytics" screen. This shows your own business figures (revenue, profit, top customers, order trends) calculated on your device from your own records. It is not usage tracking, and nothing from it is transmitted anywhere.

4. How Your Data Is Stored

• Local database: all records are stored in a SQLite database in the app's private storage on your device. On Android, this area is not readable by other apps.
• Backup files: the app can export your data as a backup bundle (.abb), a JSON file, a raw SQLite file, or CSV files.
• Optional backup encryption: in Settings → Backup & restore you can set a backup password. When set, every new .abb backup bundle — local exports and Google Drive backups — is encrypted with AES-256-GCM, using a key derived from your password (PBKDF2, 150,000 iterations). The password itself stays in the app's private storage on your device and is never included in any backup, and is never sent to us.

Please note:

• Backup encryption is off until you set a password. Without one, .abb backups are unencrypted, and anyone who obtains the file can read everything in it, including your customers' contact details.
• JSON, raw SQLite and CSV exports are always unencrypted — they exist to be readable and portable. Treat them as confidential.
• If you forget your backup password, encrypted backups cannot be opened — by you, by us, or by anyone. There is no recovery or reset. Keep the password somewhere safe.

5. Google Drive Backup (Optional)

Cloud backup is entirely optional and is off until you connect an account. If you enable it:

• You sign in with your own Google account. Backups are uploaded to your Google Drive, into a visible folder named 3DPrintingStudioBackups. They are not uploaded to us, and we cannot see them.
• We request only the drive.file permission. This is the narrowest Drive permission available: it lets the app see and manage only the files the app itself creates. The app cannot see, read or touch any other file in your Google Drive.
• Account information we handle: your Google account email address and an access token, used solely to sign you in and upload to your Drive. These stay on your device.
• Scheduled automatic backups: if you turn on automatic backup and stay signed in, the app uploads a backup to your Drive on the schedule you choose (daily, weekly or monthly) without asking each time. The app keeps the newest five automatic backups in your Drive and deletes older automatic ones; backups you made manually are never auto-deleted. You can turn the schedule off at any time in Settings.
• Your control: you can back up, restore, list and delete backups from within the app, disconnect the account at any time, or delete the folder directly in Google Drive.
• Backup contents are encrypted only if you have set a backup password (see section 4). With a password set, the file uploaded to Drive is AES-256 encrypted and Google cannot read its contents; without one, it is an unencrypted archive protected only by your Google account. Either way it is stored under Google's terms.
• Google's handling of your Drive data is governed by Google's Privacy Policy.

Limited Use disclosure: 3D Printing Studio's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including its Limited Use requirements. We do not transfer, sell, or use Google user data for advertising, and we do not allow humans to read it.

6. Account Activation (Optional)

Some features of the app are unlocked by activating your account. Activation is optional — the app is fully usable without it, and until you choose to activate, this section does not apply to you and no activation data leaves your device.

If you do activate:

• You sign in with your own Google account. We use your Google account email address only, for two purposes: to identify which account an activation belongs to (registration), and to send you a reminder when an activation is coming to an end. It is not used for anything else.
• We do not use it for marketing. We do not send newsletters, offers or promotions, we do not sell or rent it, we do not share it with advertisers, and we do not add it to any mailing list.
• What is stored: your email address, the activation's dates, and a randomly generated identifier for the device the activation is being used on. The device identifier is generated by the app; it is not your phone number, IMEI, advertising ID or hardware serial, and it cannot be traced back to you by anyone else.
• Why the device identifier exists: an activation is for one device at a time. The identifier is the only way to tell "the same phone checking again" from "a second phone", and it is used for nothing else.
• What is not sent: none of your business data — orders, customers, filament, prices or invoices — is ever transmitted during an activation check. Only the items listed above are.
• Where it is stored: in Google Firebase (Firestore), operated by Google. Google's handling of it is governed by Google's Privacy Policy.
• The narrowest sign-in available: activation asks for your basic profile and email address, and no other permission. It does not request access to your Google Drive, Gmail, contacts or any other Google service.
• How long it is kept: for as long as the account is activated, plus a short period afterwards for support and renewal. You can ask us to delete your activation record at any time by emailing netsted.infotech@gmail.com; deletion ends the activation.
• Your control: you can disconnect the account at any time in Settings. The app keeps working, with the features that do not require activation.

Limited Use disclosure: our use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including its Limited Use requirements.

7. How Activation Periods Work

This section is about the commercial terms of activation, rather than about privacy. It is here so that everything about activation is in one place.

• Periods run on the calendar, not on usage. An activation covers a fixed period, and that period runs to the end of its final day — not to the clock time it was activated at. It continues to run whether or not you open the app, and unused time does not roll over or extend.
• Activation periods are not cancellable and are not refundable once started, except where a refund is required by law or by the rules of the store you purchased through. Purchases made through Google Play remain subject to Google Play's refund policy, which applies regardless of anything stated here.
• We record when your activation began and when it ends. These dates are held with your activation record (section 6) so that both of us can see the same thing.
• What we provide is activation, and only activation. We do not host, store, process or have access to your business records at any point.

Your data is yours, and it is your responsibility. This is worth stating plainly:

• Your records live on your device. Your backups live in your own Google Drive, under your own Google account.
• We operate no storage of your business data and have no copy of it. If your device is lost, reset or damaged, we cannot recover anything for you — we have nothing to recover from.
• Keeping backups is your responsibility. Please take them regularly, and check occasionally that you can restore one. If you use a backup password, keep it somewhere safe: without it, an encrypted backup cannot be opened by us, by Google, or by anyone else.
• An activation ending does not delete, lock or withhold anything you have saved. Your records stay on your device, remain readable, and local backup and export keep working.

8. Sharing Invoices

The app can generate a PDF invoice for an order and let you share it. Sharing only ever happens when you tap to do it. When you do:

• The invoice is handed to the app you choose — for example WhatsApp, your email client, or the Android share sheet.
• The invoice contains order details and the customer's name and contact information.
• Once handed over, the receiving app and service handle that file under their privacy policies, not ours. Please make sure you are comfortable with the app you send it through.

9. Permissions the App Requests

• Internet / network state: used only for Google Drive backup and, if you activate your account, for the activation check. With neither in use, the app makes no network calls of its own.
• Notifications: to show the reminders you schedule.
• Exact alarms: so a reminder fires at the time you set rather than being delayed, and so a scheduled automatic backup runs at its set time (12:00 AM).
• Run at startup: so scheduled reminders and automatic backups survive a device restart.
• Ignore battery optimizations (optional): asked only when you turn on automatic backup. Battery savers can silently stop the scheduled midnight backup; granting this exemption keeps it running. You can decline — backups will then also run when you next open the app.

The app does not request access to your contacts, camera, microphone, location, photos or SMS.

10. Data Retention and Deletion

• Records in the app: kept until you delete them. Deleted customers and filaments go to a recycle bin and can be restored from the Recover screen, or removed permanently.
• Uninstalling the app removes its local database and its local backup files from your device.
• Google Drive backups are NOT removed by uninstalling. They remain in your Google Drive until you delete them — from the app, or from Drive directly. If you want them gone, delete them.
• Files you exported or shared (invoices, CSV or backup files sent to other apps or saved elsewhere) are outside the app's control and must be deleted by you wherever you put them.
• On our side: none of your business data — we never receive it. The only record we hold is the activation record described in section 6, and you can ask for that to be deleted at any time.

11. Data Security

• No transmission to us: your data never reaches a server we operate, because we operate none.
• App-private storage: the database lives in the app's private directory, which other apps on the device cannot read.
• Minimal cloud permission: only drive.file — the app can never see the rest of your Drive.
• No third-party analytics or trackers are embedded in the app.
• Optional AES-256 backup encryption: setting a backup password encrypts all new .abb backups (section 4). JSON/SQLite/CSV exports remain unencrypted by design.
• Android's own app-data backup is switched off (allowBackup=false): the operating system is not allowed to copy the app's private database into its own cloud backup. The only copies of your data that leave the device are the ones this app makes under the rules above.
• The app has no screen lock or biometric lock. Your device's own lock screen is what protects the data on it. We recommend you use one.

No method of storage or transmission is completely secure, and we cannot guarantee absolute security.

12. Third-Party Services

The app uses these third-party services, and only when you choose to use the corresponding feature:

• Google Sign-In and the Google Drive API — for optional cloud backup (subject to Google's Privacy Policy)
• Google Sign-In and Google Firebase (Firestore) — for optional account activation, storing only your email address, the activation dates and a generated device identifier (section 6)
• Apps you share invoices through — e.g. WhatsApp or your email client (subject to their own privacy policies)

We do not sell, rent or share your data with anyone, and we do not use it for advertising.

13. Children's Privacy

3D Printing Studio is a business tool intended for adults running a 3D-printing operation. It is not directed at children under 13, and we do not knowingly collect data from children.

14. International Users

The app runs entirely on your device, and none of your business data is transferred internationally by us. If you enable Google Drive backup, or activate your account, the data described in sections 5 and 6 is stored in Google's infrastructure and Google's data-handling practices apply. Google operates globally, so that data may be processed outside your country.

15. Changes to This Policy

We may update this privacy policy from time to time. Changes will be reflected in the "Last Updated" date above. Continued use of the app after a change constitutes acceptance of the updated policy.

Summary

• ✅ Your business data stays on your device — orders, customers, filament and prices are never sent to us
• ✅ Account activation is optional and sends only your email address and a generated device identifier — used for registration and activation reminders, never for marketing
• ✅ No analytics, no tracking, no ads
• ✅ Cloud backup is optional, goes to your Google Drive, and uses the narrowest possible permission
• ✅ You can export, restore and delete everything yourself
• ⚠️ Backups are yours to keep — they sit in your own Google Drive, we hold no copy, and we cannot recover your data for you
• ℹ️ Activation periods run to the end of their final day and are not refundable once started, except where the law or the store requires it (section 7)
• ✅ Optional backup password encrypts your .abb backups with AES-256 — with no recovery if you forget it
• ⚠️ Without a backup password, backups are unencrypted; CSV/JSON exports are always readable — keep them safe
• ⚠️ You are responsible for the customer details you choose to store