The activities were most common with those aged between 14 and 34.
Apps such as WhatsApp, Skype, Viber, Facetime and iMessage offer users free texting and calling as long as they are connected to the internet.
The Roy Morgan survey showed 47.4 per cent of Kiwis over 14 said they used the internet on a smartphone in July, compared with just 11.6 per cent in the same month of 2010.
Slingshot recently launched its 1GB data-only plan as a direct response to consumers only wanting the service.
Slingshot general manager Taryn Hamilton said not only was mobile data traffic growing, but app quality was improving - attracting more people to the platform.
"We can see from our customers' usage patterns that data use roughly doubles every 18 months across both home broadband and mobile plans.
"More people are watching video online, smartphones have become mainstream, and there's loads of apps available that people are using to substitute for calling and texting."
He said the number of calls people made were "dropping year on year".
At Spark, app use was contributing to a 25 per cent decline in text messaging since 2011, said spokeswoman Lucy Fullarton.
"While texting and calling are still a popular way of communicating amongst our customers, we are definitely seeing a decline as many people begin using 'over the top' services, like Viber or Facebook Messenger.
"It's hard to measure the extent to which people are substituting text/calling for data services precisely, but we've seen massive uptake of social media over the past few years."
Spark Socialiser - a plan which gives customers 1GB of free data for use on social media apps - has been one its most popular products ever.
Vodafone consumer director Matt Williams said the company expected its percentage of smartphone use to hit 90 per cent by the end of 2015.
"Our customers still love to talk and text ... but data is the future," he said. "That's why our focus is on 4G, so that our customers can continue to get the best network experience, whatever they're doing."
Chief marketing officer at 2degrees, Malcolm Phillipps, said smartphone usage had increased dramatically, with about 60 per cent of its customers now using smartphones, compared with just 20 per cent three years ago.
"Our observation is that people are just using their phone more. We haven't seen a decline in texting and calling, but we haven't seen the rise in those like we have in mobile data," Mr Phillipps said.
"There is definitely an increase in people using things likes WhatsApp, Viber and Skype."
However, he said using apps depended on the other party also using the same one.
Facebook all the way for instant communication
Auckland medical student Minoru Moore, 32, does nearly all of his communication with friends and family through Facebook on his smartphone.
"If you have conversations over Facebook Messenger all the messages archive on your phone just like SMS," he said.
"It's really useful for group messaging like trying to organise your activities with people because it's not something you can do easily with text or multiple phone calls."
Mr Moore said he also used Snapchat and WhatsApp regularly, and text messaging and phone calls were least used by a large margin.
"I originally did it because it was cheaper ... it seems if you don't buy bundles of texts, it's pretty expensive to hold ongoing conversations using SMS."
He said it was not just younger demographics using the services, either.
"My mum is half Japanese and she's picked up a Japanese message application that she uses with her friends in Japan."
