If I wanted to do some 1990s hackers shit, but more for this time period is there a way i can autopilot the apps on a smartphone that offer those crappy free numbers and auto-dial with them and feed / receive audio information into/from them via a program ?

Huh

@nitwhiz like take the app textnow
it offers sms and a voip number, an internet phone.

lets say i have a whole bunch of those, what would be a way of autopiloting them and streaming audio from a specific source do you think ?

docker ? LMAO j/k

oh i'm pretty sure there is no quick or easy way.
i could say locate all the files related to the app, use a custom file manager and capture them and then hotwire them inside an emulator and run multiple instances there of.

i could decompile the apps and figure out what protocols they're using and write clients which likely will be a simple encapsulation of voip

i modify the phone itself or compile my android and install all the apps and write something that messes with the message pump to simulate clicks and the like and also assign specific kernel devices in the background and create a bunch of virtual output/input audio devices.

these would all take forever.