Keisan Cards
Keisan Cards
An arithmetic flashcard web app for children in grades 1 to 6 that records the correctness and time taken for every answer.
What this app does
An arithmetic flashcard web app for children in grades 1 to 6 that records the correctness and time taken for every answer.
Who uses it
This is a personal tool operated by Hidenobu Nagai. Access is limited to the operator and the small number of people he has allowed. It is not a commercial product and it is not offered to the general public.
Platform
Cloudflare Workers (Next.js)
Google user data and how it is used
The email is used only to tell whether the signed-in person is a registered admin, parent or child, and to attach study records to the right family member.
- Email address of the signed-in Google Account
- The Google Account name and profile picture URL returned at sign-in (the app stores only the email)
Where the data is stored
- The app's own hosted Turso (libSQL) database holding families, members, answers and game statistics
- Cookies for sign-in and profile selection, and browser local storage for grade and sound preferences
Services that receive data
| Service | What it receives |
|---|---|
| Google Sign-In | The sign-in request and the returned account identity. |
| Google Fonts | The visitor's IP address when web fonts are loaded. |
| Cloudflare | Traffic to the app, as its hosting provider. |
| Turso | The stored application data, as its database provider. |
Note
The app calls no Google API other than sign-in.