There is  such a thing as  a voice  switch that could be used with switch control to perform  the functions that Siri won't do:

I don't have experience with these, and would probably want to use a more "traditional" switch, but just wanted to throw this out there.

I know Hey Siri can allow a person w/ no hand function but a good voice to make a phone call w/ the iPhone.

My question is would Hey Siri work with a Kindle app? I hand a PALS w/ no hand function they wants to read through voice activation.

Thanks for any help