Touch-Keys
8 voice multitouch keyboard for iPad and iPhone

The patch is Pd-vanilla, but it only makes sense when running in PdParty on iOS, because it uses multitouch as input. Some other things are also exclusive to PdParty like URL (help page) and ViewPort.
That means, PdParty has to be installed on iPad or iPhone first:
https://apps.apple.com/us/app/pdparty/id970528308
see also:
http://danomatika.com/code/pdparty

Detailed description for Touch-Keys:
https://novotny.klingt.org/Apps/PdParty/Touch-Keys/TouchKeys-help-web.html

p.s.: after Download/unpacking, the resulting folders are the PdParty Scenes. The entire folders have to be copied to PdParty ‘Documents’.