This is whether pattern I use for making holders for books and tablets.
https://www.craftsy.com/sewing/project/ipad-stand/80603
It is stuffed with kapok. I have also included a book mark for my reader friends by drawing around a coffee cup twice (side by side) about 2" apart, and connecting them on top and bottom with a straight line making an elongated oval. Stitch all but about two inches on a straight side around the outside, fill it about 1/4 full with plastic beads. Stitch opening closed, then fold in half leaving half the beads at either end, and run a line of stitching through the middle. You can now flop this book mark over the top of the spine of the open book, to hold it on the right page. It is my own pattern and I have no photos, but I can draw it out if anyone wants a pattern to use.