Oscilloscope by Sound-Base Audio LLC is a free audio signal measuring tool available on Android. As the name suggests, this app is specifically designed to measure and display audio signals. It offers Scope, Meter, and FFT displays to help professionals such as audio engineers, musicians, and technicians troubleshoot audio problems, design audio equipment, and analyze audio recordings.

One of the most significant features of this app is FFT peak tracking with readout, which makes it easier to track frequency components of the signal. The app also allows users to take screenshots quickly, which can come in handy when recording and analyzing audio signals. Additionally, the high contrast colors used in the app make it easy to view the displays even in low-light conditions.

The app requires minimal permissions to function, but it must have access to the device's microphone to record audio signals and permission to write screenshots to the device's storage. Overall, Oscilloscope is a useful tool for professionals who work with audio signals and need a reliable app to measure and analyze them.