There's a certain art to hailing a taxi the old-fashioned way — poised on the curb, hand in the air, whistle or shout "Taxi!"

Or, in this evolving digital world, just tap on your smartphone. No need for roadside antics or even a phone call.

A growing number of apps are giving people the power to hail a cab or luxury sedan on their mobile device and then watch on the screen as the car approaches. At the end of the ride, just hop out, no cash necessary. The apps bill the credit card on file.

"It's 100 percent convenient," said Pete Winberg, who lives in downtown Minneapolis and uses apps with names like Uber and Taxi Magic to summon a ride almost daily. "I don't have to mess with calling if I'm out somewhere and it's noisy."

These apps are shaking up the way we get from Point A to Point B. Some services — including ride-sharing apps that help users hitch rides with strangers — have sparked battles over safety and regulation. Yet riders are embracing the apps: Taxi Magic has been downloaded more than 2 million times.

Apps for catching a ride in the Twin Cities so far are limited to Taxi Magic for cabs and Uber for luxury sedans. Minneapolis-based Blue and White Taxi, currently using Taxi Magic, is building its own app to launch this spring. Lyft and SideCar, two apps that coordinate on-demand citizen-based ride-sharing, are spreading across the country.

"I remember the days of trying to call for cabs," said Matt Carrington of Taxi Magic. Especially at peak times, "you would continue to get a busy signal. This says goodbye to all that."

Taxis go techno

Taxi Magic has been available in the Twin Cities since 2009, connecting users via computer dispatch to two local companies: Suburban Taxi and Blue and White Taxi.

Gary Tournier, president of Suburban Taxi, estimates that 10 percent of his drivers' fares come in through the app. Once someone uses the app to arrange a cab, they can track the car's progress on a map and through periodic text messages until the cab arrives.

At Blue and White, they aren't shy about telling customers to use the app rather than the regular telephone dispatch.

"It can take a while to get through on the phones on a weekend," said Drew Tibbetts, the cab company's technology manager. "To be able to sit there, press a couple taps on your phone and have a cab come to you, people like that."

Uber, the latest app-based ride system to arrive in the Twin Cities, aims for luxury.

Riders check the real-time map in the Uber app to see if there's a car nearby — typically all-black sedans or SUVs from local limo companies. After choosing a car, the driver is notified of the user's location via GPS. There's no dispatch, just drivers equipped with iPhones and the app, both furnished by Uber.

"It's us and a bunch of iPhones," said Janel Higgs, community manager for Uber in the Twin Cities. "Ours is all done through technology."

Uber rides are more expensive than traditional taxis by $5 to $10 on average and a 20 percent tip is automatically included, she said.

Wami Osman, who owns a limo company and drives for Uber between scheduled pickups, says passengers are eager to use the app. "Every week, I pick up new people," Osman said, estimating that 80 percent of his 35 to 40 Uber fares each week are using the app for the first time.

The apps have particular appeal for business travelers.

"When you go to most cities, there are many different taxi providers and it's hit-or-miss how reliable any of them are," said David Levinson, a professor at the University of Minnesota who studies transportation. "It's easier to download an app than to look up a telephone number."

Digital discord

Uber's arrival in other parts of the country has sometimes infuriated taxi drivers and local officials who say the service skirts dispatch and fare rules. For instance, Uber drivers don't have meters like traditional taxis, so riders do not see the price of their fare climbing along the way. Some critics also question safety, as drivers operate individually without a centralized dispatch.

The safety concerns are amplified around ride-sharing apps. SideCar arranges on-demand rides between private citizens driving personal cars. The company says these drivers, paid by donation only through the app, must pass criminal background checks and have an insured car in good working order. The app includes features designed to cut risk — requiring a destination input upfront, GPS tracking and user ratings to weed out bad drivers or passengers.

But app services and taxis have so far coexisted peacefully in the Twin Cities.

In part, that's because cabdrivers are more concerned about unlicensed luxury sedans circulating like cabs than they are about Uber, said Yemane Mebrahtu, president of the Minneapolis Taxicab Drivers and Owners Association. "We have limited resources," he said.

Although there haven't been disagreements, Minneapolis is developing an ordinance for taxi and ride-sharing apps, in case it's needed in the future.

SideCar recently announced an expansion to a number of cities, including Chicago. The company is looking at "the Twin Cities and beyond" but said it's "hard to say where we'll be next."

For cab-riding residents like Winberg, that would mean another option, but for now he's content with Taxi Magic and Uber. He gets a kick out of watching the car approach on his phone as he waits — comfortable and indoors — for its arrival.

"They've made my life considerably easier," he said.

Katie Humphrey • 612-673-4758