Clausen's investment firm, Startive Ventures, now holds a 12 per cent stake in Zoomy, according to Companies Office records.
Sydney-based Chris Bayley, an early Google staffer, has also invested in the app.
"It's a tribute to the success of the business that it's attracted interest from the likes of Simon and Chris," said Fisk. "Our growth plans are very aggressive and will continue to disrupt the taxi industry on a number of fronts. We believe with the additional support from investors of this calibre we will be able to fast-track the achievement of these goals and continue to evolve Zoomy's opportunities."
Bayley and Clausen have joined local investors including key staff involved in the establishment of daily deal website GrabOne.
But Zoomy might face increased competition in the form of Uber, another transport booking app that already operates in around 26 countries. The San Francisco-based company - which raised more than US$250 million last year from investors including Google's venture capital arm - is reportedly looking to employ staff in Auckland and extend its service to the city as it expands throughout the Asia Pacific region.
Fisk said it had taken many months for Zoomy to become compliant with New Zealand transport regulations.
"There's obstacles for international apps to come here and I would say those obstacles are probably higher than in other cities around the world," he said. "At some point maybe we'll have competition, but there's a few hoops to get through."
Cab Chooze, another locally-developed taxi booking app, also launched last year.
Zoomy may soon expand its service to Australia and a number of Asian cities, including Hong Kong and Singapore, Fisk said.
A payment function was added last month, which allows users to pay for their fare through their smartphone rather than paying the driver. Fisk said the system gave the app an edge against its competition.
Zoomy earns its revenue from taxi drivers, who are charged a fee based on the size of a fare.
The app can be downloaded for free from the Google Play or Apple iTunes stores.
Zoomy
* Users order, track and pay for a taxi journey from a smartphone.
* In the past three months it has been downloaded 15,000 times.
* More than 750 taxi drivers are registered to use the technology in Auckland, Wellington and Christchurch.