eWrap is a very simple cast on technique, and more useful that is obvious at first glance.
Here are some examples;
These are examples of eWrap used to cast on every second needle , knit several rows of stocking stitch, then bring the remaining needles into work, pick up the yarn between the previous needles cast on to make a neat, picot edged hem that is not bulky
These are examples of contrast eWrap cast on and contrast yarns eWrapped over the needles on work in progress to create decorative or reinforced bands or edges. Note that the embellishment is on the purl side of the knitting.