Is there a mobile app for running a node or will it have to be done at the dealership on a desktop ?
Discussion
There is a way: ofcourse it requires android because dont expect ios to give you any choice in that regard, download termux and use it for bitcoin core.
it will also show you why your node probably has to be a pruned one. I don not know of full node apps that were worth it.
the trickiest part is power and a big disk at the same time. usb-c otg cables don't always work, on some devices yes, on others, no, either the charger works or the disk works but not both. this was my exp with a 2021 motorola defy. made that phone useless as a wireless->ethernet extender because i couldn't power it as well as have it share the network to ethernet.
A mobile phone is not handy to run a full node on anyways.
What would you recommend to run a node on? Can the same machine also allow you to use sparrow?
first of all, you need sufficient storage space to host the timechain, secondly, it is beneficial if your ram is bigger, as that is one of the limiting factors in speed during setup (I believe, read that somewhere...)
so a desktop or rasperri pi with enough storage space running linux should be good.
you can also use an old computer.
or you can go over the top and iollow the guide about highly available bitcoin nodes. Link to website can be found on Bitcoin core site.