Completely redesigned decoder!
Turns your iPhone into a simple DTMF decoder. Simply hold the iPhone's microphone near to a clear source of DTMF tones (telephone "Touch Tones") and it will display the numbers being dialed. The decoded digits are also placed into a text area from which you can copy them to the clipboard.
A row of LEDs indicate which frequencies are present in the signal - each LED corresponds to a single frequency.
See it in action here:
Source code freely available:
Restored the ability to capture tones when the app is in the background.
Ratings and Reviews
Great app for professionals in the telecom industry
I use this app regularly when troubleshooting autodialers and telephone entry systems. It saved me so much time. You must adjust noise levels in order to detect dtmf tones in noisy environments.
Doesn't identify numbers quickly enough. If you want to see what number a call box is calling, for example, it misses about half of the numbers.
Only usable on an iPhone 6S Plus at full sensitivity, and works poorly then.
With Family Sharing set up, up to six family members can use this app.