With Hurricane Irma hitting Florida’s southern islands as a
category four storm, and more than 6.3 million being told to
evacuate Florida, being able to stay in contact with the
outside world is a high priority. As a result, smartphone apps
which can help coordinate rescues and responses have become
crucial to efforts.

The main one that’s being talked about — and downloaded at
a prodigious rate — is Zello, a walkie-talkie
app which was originally launched in Russia in 2007 under the
name LoudTalks (but since moved to Austin, Texas in 2011) and
now boasts 100 million users around the world. After being
featured in a Houston Chronicle story about the “Cajun
Navy” of volunteers who have been using the app to coordinate
their efforts in the wake of Hurricane Harvey, the app hit the
top of the US app store.

Zello appears to have added six million new registered users
since Monday, the company’s CEO, Bill Moore, told BuzzFeed News, and is now the top free
app on the iOS App Store. “With the crush of new users and
emergency situations, most of the Zello team is working long
days either maintaining capacity or helping with customer
support,” he said.

However, the huge interest in Zello saw the company admitting it has had to add servers to keep it

Now, with Hurricane Irma bearing down on Florida, interest in
Zello is being boosted yet again.

There’s absolutely no doubt that using a walkie-talkie app
works extremely well in tough situations, and especially
amongst volunteers who are quite simply too busy helping people
to try typing on a smart phone. Especially when, let’s face it,
their hands are wet and the weather is so bad.

However, for some reason social media is rife with incorrect
assertions that the app will still work even without a cell
signal, perhaps because it is being used in this disaster

To his credit, Founder and CEO/CTO Alexey Gavrilov has made it
expressly clear on their blog that Zello “is
not intended as a replacement for instructions from government
emergency agencies or sanctioned rescue organizations. It is
not a hurricane rescue tool and is only as useful as the people
who use it, and as reliable as the data network available. If
there is no WiFi and no cellular data service, communication
apps (including Zello) won’t work.”

Aside from that, Zello is clearly benefiting from the attention
because of the sudden interest in apps which may help rescuers
and volunteers.

“We have seen a large number of people signing up for Zello in
preparation for Hurricane Irma. Over 1 million people have
joined in the last day, with most coming from Puerto Rico and
Florida,” wrote Gavrilov.

Zello’s success may not just be down to what’s happening right
now. The app is available for a wide number of platforms,
including iOS, Android and BlackBerry, but crucially also
Windows Phone 8, Windows PCs, and LMRs (Land Mobile Radio).

It allows anywhere from two to 1,000 users to have instant,
live conversations. Users can talk one-on-one, start a channel
(like a group) or join one of thousands of existing public
channels. This too is probably why it has taken off: like
Slack, it has public channels which anyone can join.

The app is available in more than 20 languages. Zello also has
Zello@Work for companies needing a secure private network and
looking to replace two-way radio. It has a web-based console
and works with Windows rugged devices. The service is free for
up to five users.

But another startup may also benefit from this interest in
Walkie-talkie apps. Voxer in SF was built by Tom Katis, Matt Ranney in 2007 and the company
has raised $30M so far. More aimed at the enterprise, the
original idea for Voxer came to Katis when he was deployed int
he special forces in Afghanistan.

Meanwhile, interesting apps which work without cellular or Wifi
access may well be set to surge as well.

US startup Bridgefy has a user-friendly app for messaging
using only Bluetooth and Wifi, while Jott has long been a
staple of teenagers in High Schools when phone signals or wifi
are often blocked.