This case can store and protect almost every ereader : Kindle, Nook, Kobo, Booken, Sony, what else ? It can also be used for pockets books, or, why not, some diaries.
It is not really difficult to make, but you need to know how to knit intarsia and to make mattress stitch for best finishings.
The pattern is written, but you have also two charts.
You will need less than 25 gr of the five colours to knit it..
You can buy it on Ravelry for $2,50.