I found convenient in some occasions to attach my smartphone camera and specially my 360° camera on a tiny magnetic mount mostly invisible in my 360 shots. I can even hang my 360 camera up and down on metal surfaces for interesting shots.
This design is made to fits 6 disc magnets with Ø of 12 mm and height of 3 mm.
I got mines at www.supermagnete.de.
You will also need one 1/4-20 screw and nut and some piece of cork or foam.
Parts are nested and glued.