This app supports simultaneous display of the "audio waveform" and the FFT-based "amplitude spectrum" (frequency magnitude) for audio files on your device. (FFT: Fast Fourier Transform) You can check the frequency components around the current playback position while playing the file. [Features] - Simultaneous display of audio waveform and a real-time spectrum linked to the playback position. - Supports both portrait and landscape orientation. - Channel display switching (Mix / L / R). - Displays the peak level of the spectrum and its frequency. - Supports zooming in the frequency direction of the spectrum. - Pitch meter display. - Supports transcription (iOS 26 ~). [Spectrum Display Settings] - Frequency Axis: Linear, Log - FFT Size: 1024, 2048, 4096, 8192, 16384 (* 16384 is available in the Pro version) - Window Function: Hann, Hamm, Blkman, None - Octave Analysis: FFT, 1/12, 1/6, 1/3, 1, Calc Method: Max, Ave [Transcription screen] (* Available on iOS 26 or later.) Transcribes speech in the selected audio file. The results are divided into recognized speech segments and displayed in cells with their start times. Tap a cell to move to that position. The Pro version offers Ad-Free Viewing and High-Resolution Analysis (FFT size: 16384).