Privacy Policy for StahlExplorer

Last updated: 28 September 2026. This policy applies to the Android app StahlExplorer and its localised names, including SteelExplorer, with the package name com.primegeometry.stahlexplorer.

1. Controller and contact

The controller is Grassl & Schuberth GmbH, Zwischenmarkt 1, 90584 Allersberg, Germany. Privacy enquiries may be sent to code@primegeometry.com or the postal address above. Further provider information is available in the legal notice.

2. Local features and stored settings

The accompanying materials data are displayed on your device. Material selections, favourites, language, camera position, axis assignments, saved views and personal notes are stored locally. The version of the Terms of Use accepted and the time of acceptance also remain on the device. The app does not transmit this information to a server operated by Grassl & Schuberth GmbH. There is no user account and the provider does not operate its own usage analytics.

This processing enables the requested app features and, insofar as personal data are involved, is based on Article 6(1)(b) GDPR. Storing acceptance also documents the applicable terms and is based on Article 6(1)(f) GDPR. The legitimate interest is the traceable administration of the usage relationship. Necessary storage on the device is governed by section 25(2), point 2 of the German Telecommunications Digital Services Data Protection Act (TDDDG).

The app does not request access to contacts, the camera, the microphone or precise device location. Local material selections and diagram views are not passed to Google as advertising parameters. The operating system and advertising services may independently process the data described below.

Optional one-time purchases are handled through Google Play Billing. Google processes account, purchase and payment information under its Google Play terms and privacy policy. The app receives purchase identifiers, product identifiers, purchase status and a signed receipt. It verifies the signature locally and acknowledges completed purchases with Google Play. A verified receipt is stored locally to restore ad-free access and allow offline use. The app receives no card numbers and does not send receipts to a server operated by the provider. The provider can access transaction information in Google Play Console for accounting, refunds and support. Processing to perform the purchase contract is based on Article 6(1)(b) GDPR. Legally required accounting retention is based on Article 6(1)(c) GDPR.

Google Play may be contacted at startup and when returning to the app to check existing purchases. When a valid ad-free entitlement is already stored locally, the app neither requests advertisements nor starts a new advertising consent request at startup. Purchasing does not automatically erase previously transmitted advertising data. Existing banners are removed after purchase. Privacy options for earlier advertising use remain accessible where provided by Google.

3. Google AdMob and consent management

The free app is financed by Google AdMob banner advertising. It uses the Google Mobile Ads SDK and Google's User Messaging Platform (UMP) to manage advertising consent. No additional advertising networks are configured through AdMob mediation.

From version 1.3.1, the app applies Google's strictest age-related advertising treatment (CHILD) and content rating G to all users. No age question is asked. Personalised advertising and remarketing are disabled. According to Google, this treatment prevents transmission of the Android advertising ID and requests to third-party advertising vendors for measurement pixels or ad servers. The app also removes the Android advertising ID permission. Technical connection, diagnostic and abuse-prevention data may still be processed. These restrictions do not mean that advertising is entirely free of data processing.

For users in the European Economic Area and Switzerland, the relevant Google contact is Google Ireland Limited. Google LLC and other Google companies may participate in processing. Further information and contact details are provided in the Google Privacy Policy. Advertising technology providers involved in serving ads are identified in Google's consent interface where applicable. The absence of mediation does not mean that every ad is processed exclusively by Google.

Google lists the following data categories in particular for the advertising SDK used:

Data actually collected are processed to deliver and measure advertising and detect abuse and technical problems. The general SDK list also covers capabilities restricted by the configuration described above in version 1.3.1. In older versions, personalisation could also take place depending on consent. Data are encrypted in transit. Google provides details in its advertising SDK data disclosure.

After you accept the Terms of Use, UMP is called with the same restricted age treatment for everyone. From version 1.3.1, this signal prevents UMP from requesting European advertising consent. In older versions, UMP checks whether advertising consent is required. Technical connection data, such as your IP address, are already processed during this check. The check determines the applicable privacy requirements and implements your choices. The legal basis is a legitimate interest under Article 6(1)(f) GDPR. Necessary storage of consent choices falls under section 25(2), point 2 TDDDG.

Where consent is required, advertising-related storage and access are based on section 25(1) TDDDG and personal-data processing on Article 6(1)(a) GDPR. Non-personalised advertising is not automatically exempt from consent requirements. Technically necessary security and abuse-prevention processing may be based on Article 6(1)(f) GDPR. The legitimate interests are secure provision of the service and prevention of abusive ad requests. The purposes and legal bases offered for your particular choices are explained in Google's consent interface.

Ads are requested only when consent management permits it. Materials and diagram features remain usable without advertising consent. Accepting the Terms of Use does not constitute consent to personalised advertising.

4. Changing your choices and withdrawing consent

Required advertising privacy settings are accessible under “Model & info → Legal & privacy → Ad privacy options”. You can change or withdraw consent there with effect for the future. This does not affect the lawfulness of earlier processing. The entry is displayed when UMP makes the corresponding privacy options available.

You can also reset or delete your Android advertising ID in the device settings. Withdrawing consent or deleting the advertising ID does not automatically delete data already stored by Google. Google's Privacy Policy explains how to manage those data.

5. Recipients and international transfers

Advertising and consent data may be transmitted to Google, participating advertising technology providers and their technical service providers. Processing may take place outside the EU or EEA, particularly in the United States.

Google describes the use of adequacy decisions, including the EU–US Data Privacy Framework for covered certified recipients, and standard contractual clauses where applicable. Relevant safeguards and further information are explained in Google's data transfer frameworks. You may use the contact details above to request information on safeguards relevant to the processing of your data.

6. Retention and deletion

Local settings, views and acceptance of the terms are retained until the relevant information or app data are changed or deleted. You can delete app data through Android settings. Uninstalling generally removes local app data as well. The app does not provide its own cloud synchronisation and excludes its data from Android cloud backups and the configured device-transfer mechanism.

There is no single retention period for Google data set by the app provider. Retention depends on the data category, processing purpose, consent settings, security requirements and statutory retention duties. Google describes the criteria, deletion options and any longer retention in its data retention policy. Deleting the app does not delete data already transmitted to Google.

7. Contacting us and external links

If you contact us, we process your contact details and message to handle your enquiry. Contract-related enquiries are processed under Article 6(1)(b) GDPR. Other enquiries are processed under Article 6(1)(f) GDPR, based on the interest in responding to the enquiry. We delete correspondence after the matter is resolved once no statutory retention obligations or evidence necessary for legal claims remain. Where retention is legally required, it is based on Article 6(1)(c) GDPR.

External websites are accessed only when you open a link. The relevant operator's privacy information then applies. The app does not append material selections to linked addresses. Google's privacy information for Google Play additionally applies to installation and updates through Google Play.

8. Your rights

Subject to statutory requirements, you have rights of access, rectification, erasure, restriction of processing and data portability. You may object to processing based on legitimate interests on grounds relating to your particular situation. You may object to direct marketing at any time. You may withdraw consent with effect for the future.

You may lodge a complaint with a data protection supervisory authority, particularly where you live or work or where the alleged infringement occurred. The authority responsible for Grassl & Schuberth GmbH is the Bavarian State Office for Data Protection Supervision, Promenade 18, 91522 Ansbach, Germany.

Providing data for personalised advertising is not a condition for viewing materials. Locally required settings are needed for the features you select. The app itself does not make decisions about you based solely on automated processing that produce legal or similarly significant effects. From version 1.3.1, interest-based advertising in this app is disabled regardless of earlier choices.

9. Materials data and AI

The permission for AI use in the database licence concerns materials data. It does not permit the use of users' personal data for AI training. The app does not transmit your views or settings to an AI service.

10. Changes and access

This policy is available offline in the app under “Legal & privacy” and is accessible before you first accept the terms. Changes to data processing will be explained in an updated policy. Fresh consent will be requested only where required for changed processing.