Here goes! First time ever I write a pattern in english.
If I got something wrong, please let me know!

For this Iphone cosy;

You need:
2 ply wool  (or other yarn sutible for needles 2.5)
If you want the cosy larger use thicker yarn. One skein is enough for several cosies.

double pointed needles 2.5mm
cable needle
button

hook nr 2mm

How to:

The cosy is knitted in the round. Place a marker at beginning of row.
Co 48 sts. Place a marker at beginning of row.

Row 1: k
Row 2: p1, k2, p1, k6, p1, k2, p1, k6, p1, k2, p1, k24
Row 3-4: as row 2
Row 5: p1, k2, p1, slip 3 sts on cable needle behind piece, k3, k3 from cable needle, p1, k2, p1, slip 3 sts on      cable needle in front of piece, k 3, k3 from cable needle, p1, k2, p1, k 24
Row 6-8: as row 2
Row 9: as row 5
Row 10-12: as row 2
Row 13: as row 5

Continue like this until the cosy is big enough to house your phone.
Last row: *p1, k1*
Cast off in rib

Sew on a button

Crochet a loop: ch 26 (or as many as you need to make the loop big enough depending on where
you placed the button)
Start in second stitch, sc 25
Sew the loop on to back of cosy.
Sew the bottom part of cosy closed.

Fasten off and you are done!