Cabby Wong Hao Min has been earning up to $40 more each day since he hooked onto GrabTaxi three months ago, which brings his daily collection to more than $250.
He says the mobile booking app lands him at least five jobs a day and is especially useful when he takes passengers to remote areas such as Tuas. "Usually, I would come back in an empty vehicle," said the 35-year-old. "Now I've a better chance to find a fare."
And it is not just taxi drivers who described the app, which was launched here last October, as a boon. In a Sunday Times online poll, about half of 207 passengers who use the app - despite some of its issues - said it has made it much easier to get a cab.
Vertex Venture Holdings, a fully-owned subsidiary of government investment arm Temasek, has shown enough faith to invest more than US$10 million ($S12.5 million) in its development here since last September.
GrabTaxi Singapore general manager Lim Kell Jay declined to reveal the number of cabbies and commuters using the app, which was developed in 2011 in Malaysia.
But he did say GrabTaxi currently has the second-largest taxi network here in terms of cabbies using its app. It trails ComfortDelGro, the largest taxi operator.
There are other third-party taxi apps such as Brazil-founded Easy Taxi and MoobiTaxi, a Singapore start-up which consolidates booking services by the different taxi operators.
GrabTaxi is getting more popular with taxi drivers, according to 15 cabbies The Sunday Times spoke to, not least because of the perks it offers cabbies.
For the week of March 31 to April 6, those who completed at least 60 bookings got a bonus of $488. From April 7 to 13, the bonus was $188 for 40 jobs or more. The bonus varies week to week.
Cabby Louis Mai, 54, who earned more than $1,000 extra in the last four weeks for meeting the various targets, said: "It's very good income, but I don't know how long it can last."
Cabbies also gave GrabTaxi the thumbs up for telling them the passenger's destination, which allows them to better plan their schedule.
But the GPS-based app has its share of bugs.
IT engineer Oh Chee Siong, 39, said it often detects his location wrongly, making it difficult for cabbies to find him. He resorts to keying in his location manually. The Jurong West resident added: "Having to specify where we want to go also means the taxi driver can choose not to take you."
Other taxi users said it was frustrating when the app indicated there were several taxis nearby, raising their hopes that at least one would respond, only to be disappointed despite repeated tries.
Even so, undergraduate Shen Hong Sheng, 24, noted that using the app is far easier than trying to call a taxi operator. "It's a good way to get a cab."
Cabbies said they want the app, which uses Google Maps and location-based service Foursquare, to be more accurate in pinpointing a passenger's location.
The flurry of calls coming in during peak hours in the city areas means that calls keep popping up on a driver's mobile phone, making it hard for them to respond at times.
The driver version of the app is also only available for Android-based phones, which means cabbies with iOS-based iPhones are currently out of luck unless they buy a new smartphone.
GrabTaxi's Mr Lim said the company is exploring the possibility of an iOS version, but nothing is definite yet. He also added that GrabTaxi will improve the location function of its app in the next month and introduce a new feature which allows passengers to also enjoy promotions.
As for how long the company will keep on giving cabbies bonus payments, Mr Lim said: "GrabTaxi will continue rewarding our drivers for their support and loyalty in the foreseeable future."
Additional reporting by Lee Jian Xuan
