She Built an App Without Knowing How to Code -- and is Now a MillionaireFocus on what you do know -- and can do well.

As a recent transplant to Seattle, Tara Reed was sitting in her new apartment, staring at the blank walls. "I'd started to get interested in fine art, and it struck me how annoying and labor-intensive it would be to find art I liked for my new place," she says. "For food, music, fashion, movies, I could just tap anappand get a personal recommendation. But the fine-art world hadn't caught up to that." So, Reed, who now lives in Detroit, helped it catch up: She launchedKollecto.

Related:What Married Founders Learned About Running a Business