Due largely to its single-material design, it’s fair to say Rowan is the least complex of the bunch. A rear piece of sturdy rubber has a checkered texture, with raised, crosshatched squares contrasting with flat ones. That piece lays on top of a second piece of rubber that forms the body of the case along with a border running around the front edge. These are two-tone designs on four of the five color options, although there’s also a black-on-black…