Notes:
Gimp yarn is completely non-stretchy so be sure to work tightly and evenly. For this reason I highly recommend using 2 circular needles (as in sock knitting) as this avoids ladders forming between the needles.

The flap is knit as a small tube in order to hide the back of the magnet where it is fixed to the knitting. If you are making this without a magnet, and using instead a buttonhole and button, you do not have to knit the flap as a tube. I leave it to you to modify the pattern as such.

This pattern would work equally well with a tightly spun wool or blend yarn. You could also knit the apple pattern in a second color as intarsia knitting.
You could as well avoid the magnet all together and make a button hole in the flap and sew a button on the pouch itself.
The possibilities are many!