I was very nervous about using the product at first, it seemed to cost so little to protect something so expensive, so I tried it out with tissue paper first in the sink. Tissue paper survived, as has my iPhone after 2 holidays now.
It gave me piece of mind just having my phone around the pool and on the beach but was good to be able to take pictures and videos in the water. As the description says, touch screen doesn't work underwater but you can use video if obviously you start it above the water.
Would recommend to anyone just for the peace of mind on holiday.