You might already be using this type of tape for sewing zippers and know just how wonderful Wonder Tape is, but if not let me tell you about it because it's become something I make sure to always have around.
The Improv Zip Wristlet pattern is the first time I specifically recommended and used it in the pattern instructions. The zipper installation in this pattern is the most complicated of all my patterns (though it's not terribly hard) and taping it in place makes it easier. Really it makes all zipper sewing easier.
I first picked up a roll of this tape to sew an invisible zipper in a skirt. Invisible zippers aren't something I don't have a lot of experience sewing, and Gina at Bolt recommended the tape, and it worked out beautifully. Then it took a while to get in the habit of using for zippers in pouches, but now it's my go to thing when sewing any zipper.
When using it for zippers, I don't tape down the entire zipper, but just use a few small pieces. Usually the magic number is three 1.5" or so pieces--one at each end and one in the middle. If you are newer to sewing, you might like to tape the whole length of the zipper to really hold it on in place firmly.
It doesn't gum up your needle and though it does wash away it doesn't have to be removed. If you put it on next to the very edged of the zipper tape, most or all of it will be hidden after you sew on the zipper.
The other place I use this tape is for VELCRO (yes, they ask you spell it like that). Before using this tape my VELCRO almost always ended up slightly off kilter no matter how hard I tried to keep it straight! So it's nice to not be looking at crooked VELCRO anymore. It was a minor annoyance, but like most of us sewing and especially when you are selling what you make, it's always more satisfying when everything turns out neat and tidy and straight, straight, straight.