SpectrumView Plus is a dynamic audio companion for iPhone, iPad, and iPod Touch, offering real-time visualization of frequencies audible to the human ear and beyond. With a high-quality spectrogram and spectrum analyzer display, this application is a versatile tool for various acoustic analyses. Users can measure vocal range, analyze speech frequencies, calibrate instruments, identify noises, and more.

Key features include the ability to refresh the spectrogram, customize scale values, set recording filenames, access recordings via the "Files" app, and transfer files via web browser. The app supports logarithmic scales, peak hold, location tagging, multiple sample rates, and high-frequency resolution. Users can record, playback audio files, zoom into specific frequencies, and share recordings easily. SpectrumView Plus also offers SoundCloud support, fullscreen mode, customizable color scales, window functions, gain application, and direct file opening.