Privacy Policy

// DENDOU — Electric Circuit Simulator

Introduction

The app "DENDOU" (the "App") is provided by Fuji Bit (the "Operator"). We respect your privacy and are committed to protecting personal information. This policy explains how information is handled in the App.

Information collected

The Operator itself does not collect information that identifies you. The App has no account and never talks to a server of the Operator. However, the third-party services built into the App may collect the following.

• Advertising data (Free version): the App shows ads through Google AdMob (an advertising service operated by Google LLC). The Google Mobile Ads SDK starts only after you have answered the question described under "Ads and your ad choice" below (the App's own ad choice on Android, the system tracking prompt on iOS); until then the ad SDK collects nothing and no ad is requested. After that, for ad delivery, measurement, analytics and fraud prevention, the Google Mobile Ads SDK may collect the following and share it with Google's advertising partners:
  • Device identifiers (the Android advertising ID; on iOS the IDFA, only if you allow tracking under App Tracking Transparency and have not switched "Ad settings" to "Don't allow")
  • IP address and the approximate location inferred from it (country, region or city level)
  • Device information such as model, OS version and language
  • Interactions such as ad views and taps, and app usage
  • Diagnostics such as crashes and performance
  See the Google Privacy Policy and How Google uses information from sites or apps that use its services for details.
• In-app purchase data: purchases of the Pro version are managed by Apple (App Store) or Google (Google Play). The App only checks whether Pro has been purchased and never accesses payment details.

Information not collected

The App does not collect the following.

• Information that identifies you, such as your name or email address (there is no account)
• Location from the device's location services such as GPS (the App does not request location permission)
• Contacts, camera, photos or other device data
• The circuits you create and the values you set on components (they stay on the device)
• Analytics or crash-reporting data (the Operator has not built such services into the App)

Data storage

The circuits you save (the save slots and their names, and the work-in-progress circuit saved automatically when you leave the App) and settings such as whether the tutorial has been shown and your ad choice are stored only in the device's local storage and are never sent to external servers. When you visit this website (dendou.fujibit.com), as with any web request, your device's IP address and User-Agent may be recorded for a limited period in the hosting provider's access logs; this information is handled only to operate and secure the site, and the Operator does not use it to identify you.

Ads and your ad choice

The Free version shows a Google AdMob banner at the bottom of the screen. On first launch, the App asks whether it may show personalized ads. How and when it asks depends on the platform.

Android: after the splash screen and the tutorial, the App asks on its own screen, "May we show ads based on your interests (personalized ads)?". The question includes a link to this privacy policy.

• Until you answer (the default): the ad SDK is not started and no ad is requested, so the ad SDK collects nothing. If you close the question without answering, it is asked again on the next launch.
• "Allow": ads are shown, including personalized ads.
• "Don't allow": ads are still shown, but they are not personalized (the App marks its ad requests to the Google Mobile Ads SDK as non-personalized, so only non-personalized ads are served).

iOS: right after the splash screen (before the tutorial), the App shows no screen of its own; it asks through the system App Tracking Transparency (ATT) prompt.

• Until you answer (the default): the ad SDK is not started and no ad is requested, so the ad SDK collects nothing.
• "Allow": ads are shown, including personalized ads.
• "Ask App Not to Track": ads are still shown, but they are not personalized.
• If the prompt could not be shown: non-personalized ads are shown for that session, and the App asks again on the next launch.

On both platforms you can change whether ads are personalized at any time under "?" > "Ad settings" in the App by choosing "Allow" or "Don't allow"; the change applies immediately (on iOS, this is available once you have answered the tracking prompt).

The Pro version shows no ads and never asks these questions ("Ad settings" is not shown in the menu). If you return to the Free version, for example after a refund, you are asked at that point if you have not answered yet.

In regions where the law requires consent, such as the European Economic Area, the United Kingdom and Switzerland, Google's consent management platform (User Messaging Platform) shows a consent screen after you have answered the question above (on iOS, after you have answered the tracking prompt and closed the tutorial). No ad is requested until consent has been confirmed there. You can change or withdraw that consent at any time under "?" > "Ad settings" > "Privacy choices (Google)" in the App (shown only in regions where consent is required).

Advertising identifiers and opting out

On both platforms, you can stop personalized ads at any time by choosing "Don't allow" under "?" > "Ad settings" in the App.

On Android (Free version), the Google Mobile Ads SDK uses the advertising ID for ad delivery. You can delete or reset the advertising ID and turn off personalized ads under "Ads" in your device's Settings app (Google ad settings; depending on the device it is under "Privacy" or "Google").

On iOS (Free version), the Google Mobile Ads SDK can read the IDFA only if you choose "Allow" in the ATT prompt. If you choose "Don't allow" under "Ad settings", ads are not personalized even when ATT is allowed. If you choose "Ask App Not to Track" in the ATT prompt, ads are still shown but the IDFA is not used. You can change the ATT setting at any time in Settings > Privacy & Security > Tracking.

Information sent to third parties

The list of information the App sends from your device (recipients, content, purposes) is on Information sent to third parties.

Third-party services

The App uses the following third-party services.

• Google AdMob — ad delivery and consent management (Free version only)
• Apple StoreKit — in-app purchase (iOS)
• Google Play Billing — in-app purchase (Android)

In-app purchases and payment information

Payment for the Pro version (a one-time purchase) is processed by the App Store or Google Play. The App never receives or stores payment details such as card numbers. It only reads whether Pro has been purchased, and uses that solely to unlock features on the device. If a purchase is refunded or revoked, the App automatically returns to the Free version.

Retention, deletion and your rights

All of the App's data (circuits, settings) is on your device and is deleted when you uninstall the App. The Operator holds no data linked to you, so there is no data to disclose or delete on request; feel free to contact us with any question.

Requests to access or delete data collected by Google AdMob can be made to Google as described in the Google Privacy Policy. Purchase history is governed by Apple's or Google's policies.

Children's privacy

The App is a learning app for general audiences interested in electric circuits and is not primarily directed at children under 13. The App does not knowingly collect personal information from children under 13. If a child uses the App, parents may consider the Pro version (no ads) or the device's ad settings.

Changes to this policy

This policy may change without notice. When it does, this page is updated along with the date below.

Operator and contact

Operator: Fuji Bit
Privacy questions: info@dendou.fujibit.com (see also the support page)

Effective: October 25, 2026
Last updated: November 10, 2026