Privacy Policy

Khrap&Kha (“the app”) helps parents learn basic Thai. It is published by 4Envelopes. This policy explains what happens to your data in the app and on this website.

What we don’t do

The app has no accounts, no advertising, no analytics and no tracking. We don’t sell or share personal data. This website uses no cookies or analytics.

Data on your device

Your chosen interface language and gender (used to pick the right Thai words), downloaded lessons and audio, and your latest practice recording are stored only on your device. Uninstalling the app deletes them.

Lessons and audio

Lessons and the speakers’ recordings are downloaded from Cloudflare’s content network. Like any web server, it receives your IP address and standard request information to deliver the files.

Pronunciation practice and the microphone

The microphone is used only while you record a phrase in pronunciation practice, after you allow access. The recording and the Thai phrase are sent over an encrypted connection to our server (Cloudflare Workers), which forwards them to Microsoft Azure AI Speech to score your pronunciation and returns the score. We don’t store your recordings or use them for any other purpose. Microsoft processes the audio in memory to produce the result and does not store it. Melody (tone) analysis happens on your device.

Children

The app is intended for adults. It is not directed at children under 13, and we don’t knowingly collect their data.

Your rights

We keep no personal data on our servers, so there is nothing to access, correct or delete there. To remove local data, uninstall the app. You can withdraw microphone access at any time in your phone’s settings.

Changes and contact

If this policy changes, we will update this page and the date below. Questions: sergei@4envelopes.app.

Last updated: 2026-10-25