Sound Test is a free Android app developed by Upper.cz under the Multimedia category and subcategory Music & Radio. The app allows users to play sounds in the general human hearing range of 20 Hz - 20 kHz. The app's main feature is to help users determine what frequencies their ears can hear and to find their favorite frequency to share with friends over email or SMS.

The app's interface is simple and user-friendly, making it easy to navigate and use. Users can choose from a range of frequencies and play them for a set amount of time. The app also includes a feature that allows users to set a timer for how long they want to play the sound.

Overall, Sound Test is a great app for anyone interested in exploring the range of sounds their ears can hear. The app's simplicity and ease of use make it a great choice for both casual and serious users.