Air Qin · Terms of Use

1. What the app provides

Air Qin (無絃琴) is a virtual guqin played in the air through camera-based hand tracking, available as a web app and a mobile app. The instrument itself — seven strings and thirteen hui, every playing technique, and recording — is free forever. “Zhiyin” is a one-time purchase that adds the full score library, the custom seal, and additional tone presets, including pieces added to the library later. Locked pieces can be previewed by everyone.

2. Purchases, restoration, and refunds

In-app purchases are completed through the Apple App Store at the price shown on the store page. After switching devices you can use “Restore Purchases” to recover your entitlement with the same Apple ID. Refund requests follow the Apple App Store refund policy and must be made to Apple; we cannot process refunds directly. The web version is a free trial channel and offers no purchases.

3. Intellectual property

• The software, interface design, name, and marks of this app belong to the developer;
• Pieces marked “移植” (transposed) are guqin arrangements of folk or public-domain melodies; pieces marked “意临” (free rendering) are original arrangements evoking the mode and texture of classical pieces. All are produced by the developer;
• The performance videos you record are yours, free to share and publish (they include the product’s seal and closing frame);
• Unauthorized commercial copying, distribution, or resale of the app is not permitted.

4. Safe and sensible use

Playing in the air requires arm movement. Please make sure you have enough space around you, away from fragile objects and other people, and rest between long practice sessions. Do not use the app while driving, walking, or in any other situation that requires your attention.

5. Changes and disclaimers

We keep improving the app; features and the score library may change or grow. Entitlements already purchased under “Zhiyin” will not be reduced by updates. The app is provided “as is”; hand tracking depends on device performance, lighting, and environment, and no specific recognition accuracy is guaranteed. To the extent permitted by law, the developer is not liable for indirect losses arising from use of the app.

6. Changes to these terms and contact

If these terms change materially, we will update the date on this page and notify you inside the app; continued use constitutes acceptance of the updated terms. For questions, contact liujunshuo1987@gmail.com. These terms are governed by the laws of the People’s Republic of China.

For privacy details, see the Air Qin Privacy Policy.