Someone asked for one more phone astro pic so here it is

Not OP but i often just use the timer in these cases. I also have a cheap bluetooth remote that was included with a selfie stick ten years ago(got it for the 1/4" thread to put my phones on a tripod).
But atleast on android you can also use most bluetooth game controllers as a remote to release the shutter. I snapped quite a few pics with my xbox and 8bitdo(small and pocketable) controllers over the years.

Edit: Which reminds me that my old DSLR had a IR receiver for remotes. So i often just borrowed my parents tv remote in the night because one random button had the same ir signature as the official camera remote of the manufacturer. Good times

Set it with timer and tapped the screen