In some European countries taxi operations are heavily regulated, so Uber and Lyft have a limited or no presence. FREE NOW (formerly mytaxi) is a good alternative.
FREE NOW is a black cab and taxi booking app for hailing rides on licensed taxis in around 100 cities of 10 European countries. There are all the basics such as booking rides and estimating fares. Plus full integration with the Google ecosystem.
It takes one tap to sign up with a Google account, one tap to set up Google Pay as a payment method, and one tap to pay the fare.