I wanted to knit a resting place for my mobile and came up with this. As a Whovian I inserted a TARDIS, but the pattern even works without it.

Gauge is not important, any yarn can be used, thicker yarn only gives larger pyramids.
The smaller one is perfect for an iPhone (see photo), the striped, larger one holds my kindle fire 7” easily.

I knitted two other resting places: one with 8 mm needles and yarn 56 m / 50 g: bottom square gives 16 cm x 16 cm (grey one). That pyramid holds a DIN A4 book easily.

The download includes the pattern in both German and English!