There’s no shortage of channels for companies to connect with their employees, from email and social media to custom-built platforms. Yet, most technology has been focused on employees who spend their days working at desks or glued to their smartphones.

What about the 75 million Americans – more than half of the workforce – who work behind cash registers, in kitchens, on factory floors or at job sites? “This group has been completely overlooked,” says Jonathan Erwin, founder and CEO of Red e App.

A 24-year technology veteran at such companies as Microsoft and Hosting.com, Erwin didn’t give much thought to this segment population until he moved back to his hometown of Louisville, Ky. to work on a different idea, a messaging platform focused on connecting businesses with consumers. “When I started talking with companies, they said ‘we have a million ways to reach consumers,’” says Erwin, age 47. “What they really needed was a better way to communicate with hourly employees, who either don’t have corporate email or don’t check it regularly.”

Launched in 2011, Red e App can be downloaded to smartphones or computers, giving employees easy access to training, scheduling and benefits information, as well as frequently-used numbers. Scheduling changes or emergency alerts can be sent to specific people or groups, such as those in a particular region or type of job, and show up like text messages, saving managers from wrangling with phone calls. And unlike voice messages, when a staffer reads a notification or accesses a file, his organization knows it.

The app is now being slowly phased in at companies as General Electric and Papa John’s International to keep more than 10,000 employees up to speed on everything from benefits changes and job openings to crisis management.

Entrepreneur spoke with Erwin about why traditional platforms have overlooked a critical segment of the working population.

Entrepreneur: For those of us who are at a desk most of the day, it’s hard to understand why companies have struggled with how to communicate with such a large segment of the population. Why is that?
Erwin:
Their behavior is different. Many of these people come in and out of those hourly markets or switch jobs frequently. They typically don’t have corporate email or don’t have time to check it while they’re working. Consider a nurse. She’s working for 12 hours doing nursing activities. If she wants to interact with her company, she typically needs to do it on her own time, and then it means logging into email or a company website and weeding through vast amounts of information. It’s the same for a restaurant worker, retail person or a factory worker.

Related: Don't Stop Recruiting Employees Once They're Hired

Entrepreneur: How do most companies communicate these employees?
Erwin: Single sheets of notices or paper stuffed in payroll envelopes and mailed to people’s houses. There are human resource office hours, kiosks on factory floors, and bulletin boards or videos in the break room. All of these are cumbersome, slow and not very effective.

Entrepreneur: If these employees haven’t adopted email, why are they likely to use an app?
Erwin: We’ve found is that most of them have mobile phones, and they’re savvy about how they use them. We try to take a very simple approach, and we encourage companies to keep their communications very targeted.

Entrepreneur: Have companies gotten pushback from employees who don’t want to use the app on their personal devices?
Erwin: They are sometimes skeptical, and that’s expected with anything new. Common concerns are what it will do to their data plans, and if their location can be tracked. Companies publish all of their policies. They aren’t collecting data and they don’t know where people are with GPS.

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Entrepreneur: Is it a one-way street, or can employees communicate with managers or each other?
Erwin: They can, but it’s through a verification process, a little like LinkedIn. Some companies give people access to a smart directory they can use to talk to each other, but they might only see the same people in their region or division. It’s not willy-nilly. It’s a very controlled and managed, and measured.

Entrepreneur: What exactly are companies measuring?
Erwin: Companies can see if employees have read a message, and re-message those people who didn’t. In the food world, for example, you need to know who did and didn’t see a message about foodborne illness. Companies can also see who’s sending messages, who’s reading them and how quickly. It’s very different from blasting everyone with the same emails and not knowing the level of engagement.

Entrepreneur: Why is improving engagement with this workforce segment is so important?
Erwin:
Understanding who is reading corporate information regarding change management, crisis, training, logistics, scheduling and HR are all critical to business culture, compliance and accountability.  There is accountability for the employee, but also a high level of insight, attention and guidance on an individual level for the organization.  This has simply never been possible before. It is said that employees don't leave companies, they leave people.  Employees (people) want to have relationships with leadership, they want to believe in the business that they work for and that translates to pride and a sense of ownership in the work product.