Ok...here are 3 programs for the Palm Pilot. All written to scratch an itch...the best kind of software. I'm just going to post them for now and go into more detail later...you know...that documentation thingie. And source code....things like that.
PitchPipe Generates middle C to B tones.
GuitarTuner Generates the 6 notes of a standard guitar tuning. I'll be adding alternate tunings later on.
ToneGen Generates whatever frequency you enter.
All of these are donationware. Download and use freely, and if you want to contribute you can do so via PayPal.
All three programs were written in PocketC and used the CControls library. I choose PocketC because it supports a hybrid of a standard and Rapid development environment. I can program on the Palm or my desktop as I see fit, and there are GUI from developers both for the desktop and the Palm. I ultimately port everything over to the desktop so I can compile the program and release it as a standalone .prc.