Here is such a homemade product. Rocking chair for mobile phone. A second use case is possible - as a business card holder.
The execution is very simple.
Material - a furniture board, or plywood, or just a piece of board. PVA. A pair of clamps. 1 The sides of the chair are quarters of a circle, radius 96 mm. We cut it out with a jigsaw or a hacksaw and trim it with a block of sandpaper. 2 The back of the chair is a rectangle of 100 by 55. 3 The seat of the chair is again a rectangle of 50 by 55. (55 mm is the width of a small nokia. If you need to use a smartphone 65) 4 Cut from the board, grind, mill. 5 Glue the back and seat. 6 Optional - after gluing, it would be nice to align the joint from the bottom between the seat and the back with sandpaper - so that there is no unpleasant step-roughness. 7 Then we glue the sides of the chair. 8 Optional - varnish 9 And also optional - drill a hole for the charging connector so that the phone can be charged while lying in a chair. In the photographed copy, there is such a hole, it is in the seat under the phone.