Real-time spectrum analyzer and waterfall display for shortwave listeners and radio enthusiasts. Connect any receiver via cable, USB dongle, or Bluetooth and see what's on the air instantly.
SWLTools turns your iPhone into a professional-grade signal analysis tool. Connect any radio receiver and get an instant view of what's on the air.
GPU-accelerated FFT spectrum display rendered with Metal. See signal strength across the full audio bandwidth at a glance, with adjustable scaling and smoothing.
Scrolling waterfall with multiple color themes shows signal history over time. Frequency cursors let you mark and monitor specific signals. Ideal for spotting intermittent transmissions.
Built-in FIR bandpass filter with adjustable center frequency and bandwidth. Isolate a single signal before decoding to improve accuracy in crowded band conditions.
Connect a software-defined radio dongle for IQ input. Visualize I/Q components and perform advanced signal analysis beyond standard audio-only reception.
Works with the built-in microphone, USB audio dongles, or Bluetooth audio sources. Plug your receiver's headphone output into any compatible adapter and start monitoring.
Listen to the received signal through the iPhone speaker or connected headphones while the app analyzes it simultaneously. No signal splitting required.
Record sessions and export decoded text or waterfall images. Share directly from the app via Messages, Mail, or any other app on your iPhone.
Whether you're listening to shortwave broadcasts, chasing DX stations, or monitoring maritime and aviation radio, SWLTools gives you the tools professionals use — right on your iPhone.