boomer flap

The flap located on a specific style of phone case that has a wallet-like flap attached to the back of it. This style is often used by boomers for it’s “practicality”, as they can use it as a handy place to stash all their coupon cards.

“Is that Karen taking a photo of us with her phone?”
“Nah, she can’t be, she‘s got the boomer flap down”