It’s a bewildering irony to leave a hair salon looking worse than when you arrived.

“It’s when you put your hair in a bun after you get it done and say to yourself: ‘Did she even use a flat iron? It’s still so puffy,’” said Jihan Thompson, a former magazine editor and a founder of the beauty booking app Swivel. “So many times I’ve left the salon feeling like I wasted my money.”

Ms. Thompson and her longtime friend Jennifer Lambert introduced their app to digitize the hair salon vetting process for black and Hispanic women, a group largely ignored by the beauty app craze.

“Sometimes you get lucky with your 11 hours of Yelp research, but we’re trying to streamline that process,” Ms. Lambert said.

Swivel users select a desired service and indicate their hair type. The services list includes traditionally black hairstyles — cornrows, twist-outs, Bantu knots, silk press — and addresses hair types like curly, kinky and transitioning from relaxed hair to natural. Based on that information and the user’s location (Swivel is available only in New York City at the moment), the app offers a list of salons selected for their skill and service level. Either Ms. Lambert or Ms. Thompson has visited each of the salons on the app.