Jeff Long had plenty of professional connections, but he struggled to find a network of people with similar outdoor hobbies.

"I'm a climber and I had no good way to meet other climbers," he says.

His sister, Sarah Long, had a similar problem when she was skiing at the Whistler Resort in British Columbia.

"I was alone and I was looking for people to ski with," she says. "So, I actually got on Tinder and made it a point to say, 'Not looking for a hookup, but if you're here and want to ski, so am I.'"

The siblings weren't alone in their dissatisfaction, and, within a few months of launching Axis Earth, the Houston-based app has over 1,500 users.

The app is part location finder, part social media channel and part professional networking tool. Designed for enthusiasts and professional athletes of individual sports (think: skiing, climbing, surfing, etc.), Axis Earth connects them with others in their area who share their interests, giving them running or climbing partners.

"We use information input by the users and geolocation software to find them the best connections," explained Jeff. "And our algorithm filters through what they've provided us about their interests and level of participation or competition so we can give them the people who seem most compatible."

The app launched on Sept. 15, but the siblings have put in nearly two years of development.

"The first year was really fleshing out the idea, and creating a business plan that allowed us to feel comfortable being able to bring it to market," says Sarah.

The pair divided their tasks for creating the app based on their own strengths. Sarah, who's based in the Washington D.C. area, handles the business development, logistics, and operations. She founded her marketing and communications services firm called Breck — named after the Colorado skiing resort, Breckenridge. Jeff, who Sarah calls "the face of Axis Earth" and is naturally more outgoing, dealt with marketing and brand awareness.

She and Jeff did multiple interviews with athletes about the kinds of things they wanted to see in a site like this. Software teams spent six months building the back-end mechanisms that would put those opinions into practice. Then came all the front-end design.

The result is an app that can appeal, the Longs feel, to users across multiple disciplines and at multiple skill levels. Users select the sport they're passionate about and choose their level of of participation from beginner, intermediate, or professional.

"And for those who select professional, we independently validate that," says Sarah.

The app is designed for those who enjoy being active. Jeff said that they wanted something that would use technology to get people away from technology.

"I want people to be able to use their phones to put down their phones," he says. "Whether you're using the app to find other people who want to do what you do, or if you're looking at a photo someone posted and it inspires you to get out there and be more active."