I'm not even sure this would actually work with most
PDAs, but it would be nice for PocketDigi to be able to
generate CTCSS frequency tones, both alone (useful for
PMR446 radios with no built-in CTCSS software) or
together with the RTTY modulation.
CTCSS decoding would keep it all "symmetrical", even
though it's probably less useful than encoding.