I have several fp wallets, but the one I carry is the cheapest. It is made from a recycled bicycle tire. I paid $10 on Kickstarter, I believe. The profile is a little bigger than a credit card, and is divided into two equal pockets. The cards slip in from one short end, which is open. The other 3 sides are sewn shut. It does not fold.
Since the material stretches, there is almost no limit to the number of cards you can put in, within reason. Bills can be folded and slid in also, if you need to carry cash. There are no metal or leather or moving parts, just rubber and thread. It does not lose its shape. Even if you have only one card, it will not fall out. The rubbery surface keeps it from sliding out of your pocket.
One of the others I have is a nice Saddleback, but I still use this one all the time. It's probably at least 10 years old, and I don't think it can wear out. Sorry to go on so long, but I don't understand why other front pocket wallets are even being made.