We've seen plenty of cases that look like CaseCrown's Omni for iPad Air ($35) in the past, but the coverage, functionality, and price make it intriguing. The folio combines a soft touch plastic shell with a folding, fabric-covered lid. There's no button protection, but the openings are well-sized for the ports and controls they surround. As for the cover, it's divided into four columns, rather than the three of the iPad Air Smart Cover. It locks into…