Is it possible to beam TonePrints through my electro-acoustic guitar's piezo pickup via the TonePrint app? Can a cellphone with piezo based speakers beam a TonePrint from the app?
Unfortunately no, TonePrint beaming does not work with piezo devices. The speaker which is beaming the TonePrint or the pickup which is receiving it has to be magnetic. Therefore cellphones with piezo based speakers or piezo pickups on a guitar cannot encode the data in the audio stream, meaning that the TonePrint beaming does not work.
As a workaround for piezo based speakers in your phone, you could use headphones instead. For example, the standard apple ear buds and most studio headphones. This should work just fine, but they should be placed as close as possible to the pickup.
For piezo pickups, the only way to load a TonePrint is by using your computer linked directly to your pedal via a USB cable.