Nanu, the free call app created by Singapore-based start-up Gentay Communications, generated a buzz when it was finally unveiled on Tuesday.
Gentay said the app - which took the startup about eight months to develop and put on the market - was well on its way to getting 100,000 users within the first 24 hours of its launch.
Nanu is the world's first mobile voice-call app that reportedly works on all networks (even 2G) and provides free voice calls to non-nanu numbers (mobile users who have not installed the app on their smartphones) and landlines, including calls made overseas.
It follows a mobile advertising revenue model - nanu users will hear an audio advertisement instead of a ringtone while waiting for a call to be answered.
In comparison, existing players like Skype and Viber charge for voice calls made to non-users or internationally, from as low as 0.7 US cent per minute.
Nanu, currently available to Android users, will have its iOS and Windows versions later this year.
Martin Nygate, chief executive and co-founder of Gentay, told The Business Times it was a conscious decision to launch with Android.
The Google operating system accounted for some 85 per cent of 295 million units of smartphones shipped in the second quarter of this year, according to the latest report by research firm Strategy Analytics. This was followed by Apple's iOS (11.9 per cent) and Microsoft's Windows (2.7 per cent).
In terms of global market share, Android's rose from 80.2 per cent a year ago to 84.6 per cent in Q2 this year.
"This (Android's domination) is especially relevant in our key markets of developing and emerging economies, where 2G and congested 3G networks are prevalent. It is these rural areas where large populations reside that are burdened with high call costs, and do not have the ability to benefit from free calls, which are enjoyed by more affluent users in urban city centres with uncongested 3G and 4G/LTE networks," said Mr Nygate.
Clement Teo, a senior social media and mobility analyst at Forrester, said that while nanu is an interesting idea, he is unsure if it could really shake up the market here.
"It needs a large user base to draw advertisers, and I'm not sure if it can," he said.
Telcos BT spoke to did not seem overly worried about the app's entry, noting that over-the-top (OTT) services like nanu still require a telco's mobile data to work.
"Our core telco business remains strong and is the foundation of everything we do. Our superior network is the highway for mobile data traffic, and puts us in a position to take on this growing demand for mobile data," a SingTel spokesman said.
She added that market research suggests most customers do not wish to listen to marketing messages when making or answering calls, even if the service is offered for free.
Said Michael Chang, assistant vice-president of mobility at StarHub: "We do not see a major threat from OTT providers. In fact, we welcome initiatives that bring benefits to consumers. This is why we collaborate with innovative OTT providers, such as Line and WeChat, to offer our mobile customers the best social messaging experience."
He added that the telco has plans later this year to launch telco-grade rich communication service for its customers, to enrich text and calls with images and videos - all in a single app.
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