WiFi to setup a PIC based device

[richard]

On the phone, a terminal program may run and do the configuration.

simple, anything with a browser can set data fields and/or transfer files up or down to an esp8266 module of your choice
the esp can host the server on its own net or on your chosen wifi network then transfer the data to/from the pic.
With esp's asyncwebserver and or websockets you are only limited by your imagination and a little knowhow for html and js or similar scripting


ps , esp modules are as cheap as bluetooth ones and 100000 times more versatile

[Ioannis]

Bluetooth is an option I 've not though to use. Will consider it if it can be used also on iOS.

WiFi is sure more versatile. I guess setting up an ESP needs some knowledge on C, right?

Asking for a working example would be too much?

Ioannis

[richard]

I guess setting up an ESP needs some knowledge on C, right?

Yes ,
first step get a esp8266 , set up arduino for esp , install the espasync tcp and webserver libs and arduinojson too

try the examples, then try this

https://tttapa.github.io/ESP8266/Chap01 - ESP8266.html

and this
https://github.com/G6EJD/G6EJD-ESP-File-Server

when you are comfortable with the concepts ask again for some examples