Privacy Policy — Calc 3D

Last updated: August 27, 2026

1. Who we are

Calc 3D ("the app", "we", "us") is developed by Axiom 3D Studio.

For questions related to this policy or your data, please contact us:

• Email: axiomcalculator3d@gmail.com
• Instagram: @axiom_3d_studio

2. Data we collect

2.1 Data you provide directly to the app

When you use Calc 3D, you enter information about your 3D printing business, such as:

• Project, part and client names
• Material, energy and printer depreciation costs
• Sales records, expenses, delivery schedule
• Configuration preferences (language, theme, currency, custom logo)

All this data is stored locally on your device, inside the app's private storage area (Android DataStore). We, the developers, have no access to it.

2.2 Data obtained via Google Sign-In (optional)

If you choose to sign in with your Google account (to enable Google Drive sync), the app receives the following information from Google:

• Your email address
• Your display name
• Your public profile picture (URL)

This information is used exclusively to show on the Settings screen and to identify the connected account for backup purposes. We do not store this data on any external server.

2.3 Data synced to your Google Drive (optional)

If you enable "Save to Drive", the app writes a backup file (calc3d_backup.json) to the app-private folder inside your own Google Drive (appDataFolder). This folder:

• Belongs exclusively to you
• Is not visible in the regular Google Drive interface (it is a hidden app folder)
• Can be deleted at any time
• Is not accessible to the developer — only to you and your app

We use the drive.appdata OAuth scope, which is the most restrictive scope Google allows and does not grant access to any other file in your Drive.

2.4 In-app purchases (optional)

Calc 3D offers a Pro plan through Google Play Billing, available in two options:

• Pro Lifetime — one-time payment
• Pro Monthly — recurring subscription, cancelable at any time

When you make a purchase, the payment process is handled entirely by Google Play. The app has no access to your card details, bank account or any other financial information. We only receive a validation token and the type of plan purchased, both stored locally on your device to unlock the Pro features. To manage or cancel subscriptions, use the Google Play app → Payments and subscriptions.

2.5 Sharing via WhatsApp and other external apps

When you tap "Send Quote", "Add to Google Calendar" or "Open in Bitcoin wallet", the app simply opens the other app with the content pre-filled — we don't send anything on your behalf. You review the content and decide whether to send/use it. Data leaving Calc 3D at that moment is governed by the privacy policy of the destination app (WhatsApp, Google Calendar, Bitcoin wallet, etc.).

2.6 Data we do NOT collect

• ❌ We do not collect location data (GPS)
• ❌ We do not collect usage data for analytics
• ❌ We do not access contacts, photos, microphone or camera
• ❌ We do not sell your data
• ❌ We do not use advertising data to identify you individually

2.7 Advertising (free version only)

In the free version, the app displays ads served by Google AdMob. There are two formats: a banner at the bottom of the screen, and an optional video that, when watched to the end, unlocks the Pro features for a few minutes.

To serve these ads, Google collects:

• Android Advertising ID (AAID) — a number tied to the device, which you can reset or delete at any time
• Technical device data — model, operating system version, language and screen resolution
• Approximate location derived from the IP address — city or country level. We do not access the device GPS
• Ad interactions — whether it was shown, watched to the end or tapped

This data goes directly to Google. We receive only aggregate reports — how many ads were shown and how much was earned — with no information that identifies you.

Users who purchase the Pro version see no ads, and nothing described in this section is collected from them.

If you are in the European Economic Area, the United Kingdom or Switzerland, the app shows a consent screen on first launch, where you choose whether to accept personalised ads. Declining does not block the app: ads simply become non-personalised.

3. How we use the data

The data you provide is used solely to:

• Calculate costs and profit margins for your printed parts
• Generate sales and expense reports
• Allow backup and restore of your own data
• Unlock the Pro plan features after your purchase
• Personalize the interface according to your preferences

4. Sharing with third parties

We do not share your data with third parties, except when strictly necessary for the features you chose to use:

• Google LLC — provider of authentication (Sign-In), storage (Drive) and payment processing (Google Play Billing). See the Google Privacy Policy.
• Google AdMob — ad serving in the free version. See how Google uses data in advertising. Does not apply to users who purchased the Pro version.

5. Storage and retention

• Local data remains on your device while the app is installed. Uninstalling the app removes all local data.
• Google Drive backups remain in your account until you decide to delete them.
• JSON backup files exported to the Downloads folder remain there until you delete them.
• Purchase history is kept by Google Play according to its platform policy; the app only stores a local validation token.

6. Your rights (LGPD / GDPR)

You have the right, at any time, to:

• Access your data — all of it is visible inside the app itself
• Export your data — using the "Export Backup" button in Settings
• Correct or delete your data — directly inside the app, or via "Reset All"
• Disconnect your Google account at any time, in Settings → Google Drive Sync
• Revoke the app's access to your Google account at myaccount.google.com/permissions
• Manage or cancel subscriptions through the Google Play app
• Reset or delete your Advertising ID in Android Settings → Google → Ads. Deleting it makes ads stop being personalised
• Review your consent choice at any time — applies to users in the European Economic Area, the United Kingdom or Switzerland
• Remove ads entirely by purchasing the Pro version

7. Security

Local data is stored in the app's private storage area, which is only accessible to Calc 3D on Android. Communication with Google Drive uses OAuth 2.0 and HTTPS. We do not store passwords; authentication is handled entirely by Google. Payments are processed by Google Play, and no financial data passes through the app.

8. Children

Calc 3D is intended for entrepreneurs and professionals aged 18 or older. The app is not directed at children under 13 and we do not knowingly collect data from minors.

9. Android permissions used

• INTERNET — required for Google Sign-In and Google Drive
• ACCESS_NETWORK_STATE — to detect when you are offline and disable cloud features
• WRITE_EXTERNAL_STORAGE (only on Android 9 or lower) — to save backups to the Downloads folder
• com.android.vending.BILLING — required for the Google Play purchase system (Pro Lifetime and Monthly)
• POST_NOTIFICATIONS (Android 13 or higher) — for reminders about recording a sale, stalled orders and month closing. You may decline, and the rest of the app keeps working
• com.google.android.gms.permission.AD_ID — access to the Advertising ID, used only to serve ads in the free version

10. Changes to this policy

This policy may be updated as the app evolves. The "Last updated" date at the top of this page will be changed whenever there are significant changes.

11. Contact

To exercise any of the rights above, ask questions about privacy, or report a concern:

• 📧 axiomcalculator3d@gmail.com
• 📷 @axiom_3d_studio

To delete your account and the associated data, see the Account and Data Deletion page, which describes what you can erase yourself and what requires a request.