EarAgeChecker is an iPhone app developed by Katsuhisa Koike. It falls under the category of Education & Reference, specifically in the subcategory of Medicine. This free app allows users to check the age of their ears using a feature called mosquito tones.

The app is simple to use. Just press the 'Play' button to hear the sound and the 'Stop' button to silence it. By pressing the 'Play' button, you can listen to different frequencies labeled on the buttons. The age of your ear is determined by the highest frequency you can hear. In manual mode, you have the freedom to adjust the sound from 0 to 30kHz using the slide bar. This allows you to check frequencies beyond the normal audible range.

EarAgeChecker is a useful tool for anyone curious about the age of their ears and wants to test their hearing abilities. It provides a straightforward way to assess your hearing range and can be a helpful resource in monitoring your auditory health.