Silk, previously known as CM4 makes a popular wallet case but hasn't supported Samsung phones for years. That said, the popularity of the Galaxy S8 and S8+ made them change their mind.
It's called the CM4 Q-Card Wallet case. This durable polycarbonate and TPU case will protect the entire phone no matter what. Then a leather-like material rests on the back where you store credit cards and cash. If you don't want a flip case but do want a wallet, consider this option. Silk cases are durable, strong, and don't add a lot of bulk to your phone.
Along with holding three cards and cash is a built-in kickstand. There's a slot in the frame where you can use a credit card or ID as a kickstand. It's pretty good idea and adds more features to the great design. Silk now has reinforced corners and a lower price than previous years.