Lumisound turns audio into a real-time spectrogram. The same kind of visual frequency analysis used in professional audio software, now in your pocket. Use it for anything. A car engine, musical instrument, room sound, and watch the frequencies unfold in real time, colour-mapped from silence to full scale. Features: Real-time spectrogram with colour mapping Full 20Hz–20kHz frequency range Peak frequency detection with dBFS readout Export full session spectrograms as high-resolution images Audio file analysis Frequency checker Clean, minimal interface File playback Frequency generator with multiple wave shapes Decibel meter with exportable trace graph Input mic selection And all of this? Free, forever. No ads, subscriptions, or in-app purchases.