This app gives you the ability to test your speaker by generating specific sound wavelengths and tone, automatically generating a sonic sound wave, just one click to have this done. It also lets you do this process manually with a noise generator. In addition to this, the app has the builtin noise measuring, you all need to do is allow the access to speaker and press the start button Subscription terms: If you choose to purchase Gold plan, payment will be charged to your iTunes account, and your account will be charged for renewal within 24-hours prior to the end of the current period. Auto-renewal may be turned off at any time by going to your settings in the iTunes Store after purchase. Prices are in U.S. dollars, may vary in countries other than the U.S. and are subject to change without notice. No cancellation of the current subscription is allowed during the active subscription period. If you don’t choose to purchase Gold plan, you can use the app with free features. Application Terms of service and Privacy Policy: https://huong-nguyen.jimdosite.com/terms/ https://huong-nguyen.jimdosite.com/privacy/