A Chess960-support would be a great feature for the future, but
Chess for Android is really great.
p.s.:
You can install other engines.
Download Lc0 (LeelaChess0) from this site
https://lczero.org/play/download/
and one weightfile from
https://github.com/CSSLab/maia-chess/tree/master/maia_weights
and you can play against the more human-like playing AI Maia offline 
Just read up on Maia and beat M1 on L. Fascinating Project, thanks for mentioning it. Will get her on CfA now.
It's not perfect, because everytime I want to change something (difficulty or other settings) I need to reset the
UCI and reconfig the engine manually.
Maybe Chess for Android needs permission for file access.
- long press on an empty space
- UCI < reset Leela Chess Zero
- long press again
- UCI < activate UCI engine Leela Chess Zero
- Confirm the settings at the bottom
(I don't know if these are the best settings, but I found them a while ago and think that they're ok)
WeightsFile: full path to the desired file e.g.: /sdcard/Maia/maia-1500.bz.gz
CPU threads: 1
MinibatchSize: 1
maxPrefetch: 0
NodesPerSecondLimit: 0.001
(on PC there there could be other options like disable searching / node limit 1 / or NodesPerSecondLimit: 0.001
I hope this helps.
Have fun 
https://www.youtube.com/watch?v=VKtRzcVe4d4
great vid from katzenpapa re aartbik's Chess for Android app running on Pegasus. Works great for me. As long as I can't connect to chess.com I thought I'd try this.