I have a huge problem with slippery phones.
My hands are so dry, that I have to work to make touch screens function.
Worse, is slippery cases. They make the cases like hockey pucks.
Hard, and able to slide down a bar top like a pint glass in a hurry.
I had to put a small square of 1mm sticky back rubber on the back of the case, just
to keep hold of the phone and prevent me from dropping it.
.