Edit: This is my smaller, more usable version that I've started using in my daily life. [https://www.printables.com/model/661034-adjustable-phone-stand-v3](https://www.printables.com/model/661034-adjustable-phone-stand-v3) 

Phone/tablet stand with continuously adjustable angle.  Uses a friction drum/pad design to support the angle.  The action of the joint is very satisfying to play with.  Make sure the pad and drum socket are free of dust and debris or it may squeak for a while.  I haven't tried lubrication, but I haven't needed it.  

Photos use an Ipad Air 2022 for size and weight reference.  Not too big for an iphone mini in my opinion.  Size is comparable to what can be purchased online.

Tough PLA from Inland produces a good amount of friction for smooth adjustment and suffecient support.  The pads are only about half a mm larger than the drum diameter (30mm) so the forces produced come from a fairly rigid short section of plastic in the pad.  Scaling up the drum's base while maintaining the connector's size using a slicer program can increase or decrease the forces produced (3mf file provided)

(The example print in the photos lifted from the bed which is where the lines on the base come from.  That's not part of the model.)