After finding my old iPad 2 in the drawer and deciding to make use of it, I searched without success for a stand where I could have the iPad in portrait and also plugged in charging, and printable on my fairly small printer.
I've also found most iPhone stands don't allow for a case, so my iphone 8 plus hasn't fit most stands I've tried.
Thirdly, I'm working on improving my Fusion 360 skills, so this model scratches a few itches.
My iPad 2 has the old 30 pin plug, so the hole is big enough for that. Lightning fits as well, as you can can see in the photos, and USB C etc should as well, so this stand should be fine for most phones and tablets.
I've found the stand stable for my devices, but YMMV, so take all due care.
If you do print one of these, please drop me a comment or something. I get a buzz out of the thought that something I designed is being used elsewhere - Thanks!
You may want to consider supports down the middle of the arches, depending on your slicer and printer. For my printer, it's just on the edge of its abilities.