I don't know about cities, they're usually not the ones running the taxis. But taxi companies most definitely have mobile applications. In Singapore, the large

I don't know about cities, they're usually not the ones running the taxis. But taxi companies most definitely have mobile applications. In Singapore, the largest taxi company has an application that's much better than Grab. It's faster, doesn't force you to rate the drivers, and doesn't bombard you with ads in the notification area. (yes, I know Grab doesn't force you to do it anymore, but it used to be that the only way to not rate the driver was to hard kill the application)