He said dire predictions for the language had been sounded since the early 1980s and the likelihood of its dying rose as more native speakers passed on, fewer kura kaupapa Maori students transmitted the language on leaving school and nearly a fifth of all Maori shifted to Australia.
Census figures of 2006 showed 50,000 to 80,000 speakers of varying degrees of Maori who were semifluent or native speakers, he said, but since then those numbers had fallen even further to between 30,000 and 50,000.
"In two generations' time how many speakers are there going to be left ?"
He said research by Australian academic Stewart Hase argued traditional classroom learning was now being replaced by learning via mobile devices - particularly by the younger generations.
"This is a global phenomenon ... and may well provide the optimal approach to learning and Maori language revitalisation in the 21st century.
"It's good for te reo in terms of accessing a lot of our people who carry smartphones or tablets and even for those who live overseas," Dr Wiri said.
The app caters to beginners and consists of nine interactive modules in Maori language and culture with touch-screen activated technology and voice recognition functionality.
It also has more than 100 educational games and quizzes and assessments.
The app has even acquired NZ Qualifications Authority accreditation as a Maori language short-award certificate.
Dr Wiri said there was enough material for intermediate and advanced courses.
Te Taura Whiri i te Reo Maori chief executive Pita Paraone said the app was an excellent tool that was "an introduction to it for those who wish to take their learning to a more in-depth level".
A free trial of "Te Pumanawa" is available on iTunes and Google Play Store.
Maori language app
* Te Pumanawa "The Maori Language and Culture App'' at www.maori.ac.nz
* The app caters to beginners and has nine interactive modules in Maori language and culture with touch-screen activated technology and voice recognition functionality.
* It also has more than 100 educational games and quizzes and assessments.
* It is NZQA-accredited as a Maori language short-award certificate.