Red Cross says it will talk to civil defence branches after people complained they were not given enough information through their disaster app.
The Hazards app run by the Red Cross has an alert system for users to receive official emergency warnings and alerts from various agencies.
A number of people complained after not receiving information about yesterday's 7.1 earthquake and subsequent tsunami warning.
A resident on Auckland's North Shore, Jonathan Low, said he woke to the quake and logged into the Red Cross app.
"There was very little information about tsunamis or any kind of coastal disturbance."
He said there was a bit about the earthquake itself but that wasn't good enough.
"I feel that's not really adequate when people use the app to find out what they should and they're living on the coast. I think there should be a better link between Civil Defence and the Red Cross if they're running the app for Civil Defence.
"Obviously if there had been a tsunami and people had used the Red Cross app and not used other information sources they could have been vulnerable."
The product and development manager for the Red Cross, Marcus Bird, said it was up to local civil defence groups to send warnings and some had not signed up to use it.
"We provide the app free for the public to download and we've also opened up our platform and we provide that to civil defence groups so they have access, they're able to log in and push alerts out to a geo-targeted area. So we're in the process of rolling the app out around the country."
Since beginning development in October last year the app has been downloaded by 35,000 people.
Of the civil defence groups around the country the Northland, Auckland, Waikato, Wellington and Hawke's Bay have joined with Canterbury and West Coast set to launch next month.
Mr Bird said Geonet had signed up and sent out an official warning to affected areas when it happened.
"The advice in that alert that was sent out to that area was if there was intense shaking and you're at sea level to evacuate immediately and that's what a lot of the public did."
"If you're in somewhere like Auckland or Wellington, which is outside the area where the earthquake occurred, we wouldn't be waking you up at 4.30 in the morning to tell you that had happened, so we target the information only to the areas that it's relevant."
Mr Bird admitted there was work to do.
"With tsunamis it's up to local civil defence groups to assess risk and advise the public what action to take. So having a look at the Auckland Civil Defence Group Facebook page they had deemed that there was low or no threat to Auckland and therefore didn't use the app to alert.
"However we've had feedback today from the public that they really wanted to be kept informed of what's happening through the app. So this gives us an opportunity to talk with our partners and advocate that that information is also required."
As for getting more coverage across the country, he said around 85 of the CDEM (civil defence emergency management) groups would be using it by the end of the year.
"By the end of the year we should have fairly comprehensive coverage around the country and our aim is then to bring in a whole range of data feeds and alerts from any other alerting authority. So it's really the beginning of a long term project."
Gisborne's civil defence branch said it would be signing up but still relied on teaching people what to do in a disaster.
Tairawhiti Civil Defence emergency manager Louise Bennett said it was a valuable tool but education was important.
"It would be a good benefit for people who are signed up, but then the traditional way is we teach our communities that if it's a long earthquake or a strong earthquake and they live in those areas that are at high risk of a tsunami then they start moving inland. They've done that for years, all our coastal schools do that during a school day and it's something that they just know that they do.
"We still believe that the Red Cross app is important to have and we will be talking with Red Cross about that but that still doesn't affect that our communities know if it's a strong or long earthquake they start moving.
"Not everybody up the coast has the ability to have cellphone reception so therefore they need to know the signs and they need to take responsibility for that."