This is a professional piano app, you can practice piano songs and improve your piano skills at any time
There are also useful tools such as protractor.
1. the user can use the features such as analog piano and protractor for unlimited times only after subscribing through a paid subscription;
2. The subscription fee will be deducted from the user's iTunes account upon confirmation of purchase, with a free three-day trial and automatic renewal for $39.99/year;
3. users can turn off auto-renewal 24 hours before the end of the current subscription, otherwise the subscription will be automatically renewed;
4. the Apple ID of the automatically renewed subscription will be automatically deducted from the iTunes account 24 hours before the expiration of each billing cycle and the corresponding validity period will be extended;
5. Users manage the subscription service, i.e., they can go to their user accounts to set off automatic subscriptions after purchase.