Post-it Notes iPhone Case
Admittedly it’s a pretty cool idea. The purpose according to the sellers is to have a place for your notes even if your battery dies. Also it might be harder to miss these notes than the ones in your phone.
I’m just going to go ahead and presume that they will quite likely get wrinkled up in your pocket.
If for some reason you want to get one, it’s $8 and you can get it here.