Now on the App Store

Audio tools.
In your pocket.

Lumisound brings spectrogram analysis, imported file playback, decibel metering, markers, tone generation, and exports into one focused iPhone toolkit. Minimal, direct, and built for actual audio work.

Download on the App Store Free See features ↓
Lumisound app screenshot showing the spectrogram analysis interface

I got tired of not having an audio toolkit in my pocket, so, I made one.

Three focused modes

Analyze audio, generate test tones, or meter the room without jumping between separate utilities.

Analyze Record live audio or import a file, then inspect it with a logarithmic spectrogram, touch readout, loupe, zoom, pan, markers, and notes.
Generator Create test tones from 20Hz to 20kHz with manual frequency entry, presets, and a classic volume control.
Meter Use the estimated dB meter for quick level checks, recent trace viewing, dB markings, and trace exports as PNG or CSV.

Make the graph yours.

Choose from four visual themes that recolour the UI and the actual spectrogram heatmap.

Spectral
Amber Scope
Corrupted Pixel
Mono Pro

What's inside

LIVE FFT

Real-time spectrogram

Full 20Hz to 20kHz logarithmic analysis with smooth, themeable heatmap colours. Watch frequencies unfold live as sound happens.

IMPORT

Import and playback

Open local WAV, AIFF, M4A, or MP3 files from Files, analyze the full recording, then play it back with a visible playhead.

INSPECT

Touch frequency readout

Drag across the graph for an exact frequency and level readout, lock a point in place, and use the loupe for fine detail.

ZOOM

Pinch, pan, inspect

Enable the zoom workspace, pinch into paused spectrograms, pan across the recording, and inspect after zooming.

MARKERS

Notes for analysis

Drop markers onto interesting moments, add notes, revisit them later, and keep context with saved sessions.

SESSIONS

Save recent work

Name saved sessions and reopen previous recordings, markers, and analysis data without rebuilding the session from scratch.

EXPORT

Export properly

Share spectrogram images, CSV analysis data, WAV audio, full bundles, and decibel trace exports as PNG or CSV.

INPUT

Microphone selection

See the active input and choose connected microphones from Settings when iOS exposes another available source.

LOCAL

Private by design

No accounts, no tracking, no cloud dependency. Audio stays on-device unless you explicitly import, save, or export it.

Record. Inspect.
Export.

A free audio toolkit for iPhone.

Download on the App Store