For years, we’ve been told that the Internet is about to become ubiquitous, that no matter where you are, you’ll always have unbreakable, high-speed access. Well, we’re still waiting for that time. It’s not here yet, and it likely never will be. As Mike Elgin writes in Computerworld, “It’s clear that the mobile industry has finally given up on the fantasy that an Internet connection is available to all users at all times. Reality has set in.” And that’s why offline apps are so vital for any company writing mobile apps today, or tomorrow.

There are countless instances in which Internet access simply isn’t available via Wi-Fi or mobile networks, notably for field-service personnel working in remote locations. But it’s not just them. People in rural areas often have spotty service. People on airplanes or subways typically can’t get onto the Internet, either. There are also many less-developed places around the world where it’s difficult to get a connection.

Africa and Asia have the lowest Internet penetration rates in the world, yet people on those continents bank and shop using financial applications and get their news and education online — they do it via offline apps.

But even if people are temporarily out of reach of the Internet, they still need to use apps. And that’s why Serhiy Kozlov, founder and CEO of Romexsoft, writes in “Why It’s Important for Your Business to Make Your Mobile App Work Offline” that “building offline mobile applications is both critical and a huge trend.”

Kozlov notes that Africa and Asia have the lowest Internet penetration rates of anywhere in the world, yet people on those continents bank and shop using financial applications and get their news and education online. They do it via offline apps — apps that can keep working even when not connected to the Internet by using techniques such as caching.

In fact, he writes, “Even in the U.S., it is estimated that 15% of users are actually using offline apps at any given time. They are on airplanes; they are on subways; they are in areas famous for ‘dead zones.’”

And that’s why if you’re not developing offline apps, you’re failing. As Kozlov writes, “Businesses and organizations that do not build an offline app mode lose all of these people. The implications for e-commerce are obvious – customers (and thus revenues) are lost.”

It’s not just ecommerce that needs offline apps. So do industries that have field workers, like construction and oil. The transportation industry needs it as well. In fact, you’d be hard-pressed to find an industry that doesn’t need to use offline apps.