I bought a bobbin winder. I thought it was an impractical thing, but I bought it anyway. It turns out, that I love it. I have an older machine, that doesn't do a great job on winding bobbins, and it's great for that. I bought the better bobbin winder from Joanne's with a 50% coupon. I like it because it has a telescopic arm that you can wind bobbins from a large cone of bobbin thread. I don't think the simplicity one has this. I wish my BBW had a variable speed control. It winds very fast. I prefer a bit slower wind.
I would not buy a flying geese ruler. I use the no waste method that makes 4 geese at a time.
http://www.patchpieces.com/files/flyinggeese.pdf