Secure method to attach a phone to wall or floor? Answered

I would like to figure out an inexpensive and discreet way to attach a smartphone to the wall or floor (not directly - slightly set apart with e.g a rod or a lead), in a way that it is secure, and can't be easily stolen. The phone will be used as a display screen and will be resting on top of something, so needs to be relatively manouvreable. I have access to a laser cutter / clear perspex / workshop tools / ebay.