Silk Q-Card Wallet Case ($24)
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.
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.