28 Great Audio Apps for Android, Apple

FFT (for Apple) by Studio Six Digital The FFT app from Apple displays a detailed high resolution graph of incoming audio data measured as frequency versus amplitude. The app features graph smoothing for octave adjustment, parameter adjustment, peak tracking, and customizable decibel parameters. You can also save previously made graphs and calibrate the audio input for both internal audio (built-in mic) and external microphone (audio signals via the 1/8-inch input jack). The app also features a signal generator.