Privacy Policy

// DATARAKU — Last updated: October 3, 2026

Fuji Bit Inc. ("we") operates the iOS and Android app "DATARAKU" ("the App"). This policy explains how information is handled in the App.

$ Information collected

We ourselves do not collect information that identifies you. However, the third-party services built into the App may collect the following.

• Advertising data: the App shows ads through Pangle (an advertising platform operated by Bytedance). The Pangle SDK starts only after you have answered the ad choice described under "Ads and your ad choice" below; until then the ad SDK collects nothing and no ad is requested. After that, for ad delivery, measurement, analytics and fraud prevention, the Pangle SDK may collect the following and share it with advertising partners that bid for the ad:
  • Device identifiers (the Android advertising ID; on iOS the IDFA, only if you allow tracking under App Tracking Transparency)
  • 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 Pangle End User Data Privacy Policy for details.

$ Information not collected

• 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)
• Access to contacts, photos, camera or microphone

$ Personal information

The App has no account, sign-in, input forms or analytics, and we do not obtain personal information such as your name or email address through the App. However, the ad SDK built into the App (Pangle) sends device identifiers such as the advertising ID and device information directly from the App to Pangle. On their own these do not identify a specific person, but because they relate to you, we handle them as follows.

• What: the advertising data listed under "Information collected" above (device identifiers, IP address and approximate location, device information, ad interactions and app usage, diagnostics).
• Recipients: Pangle (an advertising platform operated by Bytedance) and the advertising partners that bid for ads through Pangle. Nothing is sent until you answer the ad choice on first launch.
• Purposes: ad delivery, ad measurement and analytics, and fraud prevention and security. Ads are personalized only if you chose "Allow" in the ad choice. We do not use this information for the App's features or for any other purpose.
• Third-party provision and transfers abroad: the information is sent directly from the App to Pangle without passing through us. Pangle is operated by a company outside Japan, and the information may be processed on servers outside your country. The operator, its handling and retention, and the applicable regimes are described in the Pangle End User Data Privacy Policy. We do not sell any information.
• Retention: we do not receive or store this information. The App's settings (your ad choice) are kept only on your device and are removed when you delete the App. Pangle retains what it receives according to its own policy.
• Your choices: you can stop personalized ads at any time from "Ad settings" on the home screen, and reset or delete the advertising ID or change tracking permission in your device settings as described under "Advertising identifiers and opting out" below.
• Access, correction and deletion requests: we hold no information tied to you, so there is nothing for us to disclose or delete, but we are happy to answer questions at the contact below. For information held by Pangle, contact Pangle.
• Contact: Fuji Bit Inc. (support@fujibit.com)

$ Ads and your ad choice

The App is free. It shows a banner ad at the bottom of the home screen (the structure list) and of each structure's explanation screen, and may show an interstitial (full-screen) ad when you open a different data structure from the home screen than the one you opened last (at most once every 60 seconds, and not right after launch). There are no rewarded ads. Screens that visualize data structures never show ads.

On first launch the App asks: "May we show ads based on your interests (personalized ads)?" The question (titled "About ads") links to this privacy policy.

• Until you answer (initial state): the ad SDK does not start and no ad is requested.
• "Allow": you see ads, including personalized ads.
• "Don't allow": you still see ads, but they are not personalized (the Pangle SDK is told there is no consent to personalized ads and serves non-personalized ads only).

You can change this choice at any time from "Ad settings" on the home screen; the change applies immediately.

On iOS, the App Tracking Transparency (ATT) prompt appears after this choice (whichever you pick). The App's choice and ATT are separate settings.

In regions where the law requires consent, such as the European Economic Area and the United Kingdom, the App asks for consent with the same question and passes your choice to the Pangle SDK.

$ Advertising identifiers and opting out

On both platforms you can stop personalized ads at any time by choosing "Don't allow" under "Ad settings" on the home screen.

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

On iOS, the Pangle SDK can read the IDFA only if you choose "Allow" in the ATT prompt. If you chose "Don't allow" in the App's ad choice, ads are not personalized even if ATT is allowed. If you choose "Ask App Not to Track", you still see ads but the IDFA is not used. You can change ATT at any time under Settings > Privacy & Security > Tracking.

$ Third-party services

• Pangle — ad delivery

$ Retention and deletion

The App's settings (such as your ad choice) are stored only on your device and are all removed when you delete the App. We hold no data tied to you, so there is no data for us to disclose or delete on request.

Requests to access or delete data collected by Pangle can be made to Pangle through the contact given in the Pangle End User Data Privacy Policy.

$ Children's privacy

The App is not directed primarily at children under 13 and does not knowingly collect personal information from them. If a child uses the App, please do so with a parent's consent and consider the device's ad settings.

$ Changes to this policy

This policy may be revised in line with changes in law or in the App. When it changes, this page is updated along with the date above.

$ Contact