None actually.
I have had a look at what is available and TBH anything that I would use
on my smartphone like a blockexplorer.

I have a very lo-fi^simple 'crypto' footprint, I dont day trade, I'm only interested in Bitcoin and
dont have any altcoins, I only use hardware wallets and buy and sell on Hodl Hodl,
I dont do Bitcoin on social media, I dont track the markets on a daily basis - so I
dont know if I need any apps. I am open to suggestions though!

Also what I am really looking forward to is learning to send my transactions to my
own node from my Trezor and availing of the increased security.

I envisage that most of the time this machine will be just running the node, for
everything else I use my smartphone.