Hi Jack,
I got myself a Celestron NexYZ adapter last year. I found it is good and stable with lots of adjustments.
https://www.firstlightoptics.com/adapters/celestron-nexyz-3-axis-universal-smartphone-adapter.html
My mobile phone images are nowhere near as good as I get with even a cheap astro CMOS camera, but nice for a quick image without the hassle of connecting a laptop.
Best wishes,
Andy