A dedicated booking app for a single salon faces a real adoption challenge: clients are reluctant to download an app for every business they visit occasionally, which means a salon-specific app usually only makes sense for a business with a large, loyal, repeat client base already.
For salons at that scale, the app's core value is convenience that a booking website can't quite match, push notifications for appointment reminders, one-tap rebooking of a favorite stylist and service, and loyalty point tracking, all without a login each time.
For salons not yet at that scale, a strong mobile-optimized booking website usually delivers most of the same convenience without asking clients to install anything, the booking flow, reminders (via SMS instead of push), and rebooking can all work through a browser.
The honest sequencing for most salons: prove out demand and booking volume through a mobile web experience first, and only invest in a dedicated app once there's a client base loyal and large enough to justify the download, chasing the app before the demand exists usually means an app nobody opens twice.