Turns your iPhone into a simple DTMF decoder. Simply hold the iPhone's microphone near to a source of DTMF tones (telephone "Touch Tones") and it will display the numbers being dialed. Version 1.8 not only has a far superior decoding engine, but it also allows you to tweak the sensitivity. You may copy the decoded digits to the clipboard from the text area.
Despite costing $0.99 in the iTunes store, this app remains Free Software.
Source code freely available under the GPL.
Version 1.8 is in the app store now.
Any queries, contact the author; make sure to include your email address.
Or go home.
Update 2010-09-29
Finally, a new release. This should satisfy the haters - I've replaced the decoder with band pass filters and it's now far more sensitive and discerning. It also allows you to copy the decoded numbers to the clipboard.
Thanks for the feedback people. If you haven't given me any feedback but have an opinon, then please pass it on. If you like it, give it a thumbs up in iTunes store would you?