How to use once installed on iPhone and Apple Watch:
- open iPhone app.
- open Apple Watch app and press the button.
- enjoy the juvenile humor.
Also, there are apparently several ways to spell "Whoopie Cushion" - https://en.wikipedia.org/wiki/Whoopee_cushion
*Yes I also thought I misspelled "Whoopee" *Please do not judge me for this. I swear I am a serious person in a professional setting and this made my kids laugh.