Privacy Policy for Mainspring
Effective Date: 9 June 2026
This Privacy Policy describes how Mainspring ("we", "us", "our", or "the App")
handles information when you install and use our mobile application.
Summary
Mainspring is an idle/incremental game. We do not collect any personally
identifiable information directly. Your gameplay progress is stored locally on
your device. The App uses Google AdMob for advertising, Google Play Billing for
in-app purchases, and Google Firebase (Analytics and Crashlytics) for anonymous
usage statistics and crash reporting. These services are operated by Google and
governed by Google's own privacy policies.
1. Information We Do NOT Collect
We do not collect, transmit, or store any of the following:
• Your name, email address, phone number, or postal address
• Your account credentials
• Your contacts, photos, or media
• Your precise location (GPS)
• Your device's unique hardware identifiers (IMEI, serial number)
2. Information Stored Locally on Your Device
The App stores the following data on your device only, using Android's DataStore
mechanism. This data never leaves your device unless you have enabled Google
Cloud Backup in your device settings:
• Game progress: coin balance, owned producers, upgrades, prestige currency
• Achievement and quest progress
• Tutorial completion state
• Local daily reward streak data
• Owned in-app purchase records (e.g., "Remove Ads" flag)
You may delete all locally stored data at any time by uninstalling the App or by
using the in-app "Reset Progress" option in Settings.
3. Information Collected by Third-Party Services
Google AdMob (Advertising)
We use Google AdMob to display optional rewarded video advertisements. By tapping
a "Watch Ad" option in the App, you consent to viewing an ad served by AdMob.
AdMob may collect:
• Device information (model, operating system version, language)
• Advertising ID (a resettable, non-personal identifier)
• IP address
• Approximate location derived from IP (country/region)
• Ad interaction data
For full details, see Google's Privacy Policy: https://policies.google.com/privacy
You can reset your Advertising ID or opt out of personalized advertising at any
time in your device's Settings → Google → Ads.
Google Play Billing (In-App Purchases)
When you make an in-app purchase, the transaction is handled entirely by Google
Play Billing. We do not see, store, or process your payment information. Google
may collect transaction data and payment information per its own policies.
See Google Play's terms: https://play.google.com/about/play-terms/
Google Firebase — Analytics and Crashlytics
The App uses Firebase Analytics to understand aggregate, anonymous usage patterns
(such as session counts, screen views, and feature engagement) and Firebase
Crashlytics to receive automatic crash and stability reports. These Google
services may collect:
• A non-personal app instance identifier (resettable)
• Device information (model, operating system version, language, region)
• Crash stack traces, device state at the time of a crash, and related diagnostics
• Aggregate, anonymized in-app usage events
This data is used solely to fix bugs, improve stability, and understand how the
App is used in aggregate. It is never used to identify you personally and is not
sold. For details, see Google's Privacy Policy (https://policies.google.com/privacy)
and Firebase's data handling (https://firebase.google.com/support/privacy).
Google Fonts
The App downloads fonts (Playfair Display, Inter) at runtime from Google Fonts
via Android's Downloadable Fonts API. The font request includes basic device
information per Google Fonts' policy: https://policies.google.com/privacy
4. How We Use Information
The locally stored data is used solely to:
• Save and restore your game progress between sessions
• Calculate offline earnings and daily rewards
• Track which in-app purchases you have made (so we don't show purchased items
as available)
We do not sell or rent your personal data. The only parties that receive any data
are the third-party Google services described in Section 3 (AdMob, Play Billing,
Firebase, and Google Fonts), which process it in accordance with their own privacy
policies. We do not operate our own servers and do not share your data with any
other third party.
5. Permissions Used by the App
• android.permission.INTERNET — Required to load advertisements and fonts, and to
send anonymous analytics and crash reports
• com.google.android.gms.permission.AD_ID — Required for AdMob to deliver
advertisements and for Firebase Analytics
6. Data Storage and Security
All gameplay data is stored locally on your device. We do not maintain any
server-side database of player information and have no ability to access
individual users' gameplay data. Data transmitted to Google's advertising,
analytics, and billing services is encrypted in transit.
If you have Android Cloud Backup enabled, your gameplay data may be backed up to
your personal Google Drive account per Google's backup policy.
7. Children's Privacy
Mainspring is not directed at children under the age of 13 and is intended for
general audiences. We do not knowingly collect personal information from children
under 13.
The App contains advertisements served via Google AdMob. If you are a parent or
guardian and believe a child has used the App without your consent, please contact
us at the email below and we will assist you.
8. Your Rights (EU/UK GDPR)
If you reside in the European Union or the United Kingdom, you have the following
rights regarding your personal data:
• Right to access — Since we hold no personal data on our own servers, we have
nothing to disclose. Data held by Google's services is governed by Google's
privacy policy.
• Right to deletion — Uninstall the App to delete all locally stored data
immediately. To request deletion of data collected by Google's advertising and
analytics services, use Google's Ad Settings (https://adssettings.google.com)
or contact Google directly.
• Right to opt out of personalized ads — Available in your device's Google settings.
• Right to lodge a complaint — You may lodge a complaint with your local data
protection authority.
9. California Privacy Rights (CCPA/CPRA)
California residents have the right to know what personal information is collected,
used, shared, or sold. We do not directly collect or sell personal information.
Our advertising and analytics partners (Google) may collect and share device
identifiers and approximate-location data for advertising and measurement
purposes, subject to Google's privacy policy. We do not sell personal information
as defined under the CCPA.
10. Changes to This Policy
We may update this Privacy Policy from time to time. The "Effective Date" at the
top of this page will indicate when the policy was last revised. Material changes
will be communicated through the App.
11. Contact
For questions about this Privacy Policy or your data:
• Developer: Kobasic
• Email: kobasic@gmail.com
By installing or using Mainspring, you acknowledge that you have read and
understood this Privacy Policy.