Hakarongo Mai Technical Producer George Burt says: "The translators give an English translation of what's being performed onstage, it goes beyond just a translation service it's actually the Wikipedia of Māori performing arts."
It's helping bring a new level of accessibility to the festival.
Debra Jeffcoat, who doesn't speak Te Reo, says the translation app helped her "get the whole feeling of it".
"It was really interesting to find out what they're about."
The translation service is even helping the Hastings festival reach a global audience.
Te Matatini Executive Director Carl Ross says that during the 2015 Te Matatini the live stream got two million hits.
"The majority of those hits come from Asia, so a lot of people in the world are looking at New Zealand and the first thing they see is Kapa Haka."
Te Reo Māori wasn't made an official language in New Zealand until 1987.
And while it's decline has been arrested - it still needs a critical mass of speakers to survive into the future.
The developers of Hakarongo Mai hope their app will play an important part in that.
Made with funding from