Clear Sound: Speaker Cleaner is a free lifestyle app available for iPhone. Developed by 鑫祥 刘, this app is designed to help users clean and test their speakers when their phone comes into contact with water.

The app works by providing vibrations ranging from 0 to 20,000 Hz, which can help remove water from the speaker and fix any muffled sound issues. To use the app, simply keep your phone face down and select the desired frequency on the sound generator tab.

In addition to the free features, Clear Sound: Speaker Cleaner also offers subscription options for advanced features. These include a 1-month subscription for $9.99, a 1-year subscription for $19.99, and a lifetime subscription for $Payment for subscriptions will be charged to your iTunes Account at confirmation of purchase.

Please note that subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. Subscriptions can be managed and auto-renewal can be turned off in the user's Account Settings after purchase.

For more information, you can refer to the Terms of Use and Privacy Policy links provided.