Now that Uber and Lyft have proven the demand for ride-sharing apps, a couple of other firms are trying to pry their way into the market with some new twists on the service.

Opoli (www.opoli.com), which started up in the greater Los Angeles area last year, has now expanded into San Diego — including pickups at San Diego Airport, where it is the only ride-sharing app to win official approval so far.

Opoli’s twist is that it promises “surge-free” pricing — as opposed to Uber, where prices rise as demand increases in a given area. Instead, “Opoli allows users to name their price for a desired fare, at which point nearby drivers can either accept the fare or offer a counter bid. The final price is agreed upon before pickup, with no increase in prices for peak hours or holidays, with 100 percent of the fare going to the driver,” a spokesperson said. Besides individual rides, The firm also offers eight-passenger vans.

Meanwhile, a new ride-sharing app service from South Korea is setting its sights on the New York City market.

The KakaoTaxi app has been a big hit in Seoul during its short lifetime –a market where Uber had to suspend service over security concerns.

New features from KakaoTaxi include a real-time traffic monitor so the app can predict how long it will take a driver to reach the customer’s location. And customers can send real-time location data to family or friends through the app. In Korea, KakaoTaxi drivers are required to hold the same licenses as taxi drivers.

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