BERGEN COUNTY — Think about dirt. What words come to mind? Probably soil, earth, mud and for the unimaginative, brown. But for some, dirt isn't just incidental to going outside — ideally, it's epic.

“Epic” is biker parlance for optimum riding conditions, meaning that the dirt is not too wet and not too dry. On Friday, two Bergen County natives are launching an app designed to tell mountain bike riders where they can find quality dirt.

“It’s kind of the question of every biker: where can they find epic dirt?” said Mark DiLullo, one of the app’s developers.

DiLullo and Daniel Wypler, both 27, have been working on “Muddy Tyre” for the last four months. The app, which debuts Friday on Google Play and the Apple App store, details dirt quality at mountain bike parks all over the world. The app draws on recent weather conditions to determine dirt quality, and also features hourly forecasts and rider reviews.

The friends came up with the idea while skiing in Utah together. The pair was frustrated by the difficulty in finding slope conditions. Biking intel is even less available. Wypler compared finding relevant information to “a treasure hunt” on various websites.

“Muddy Tyre lets mountain bikers connect directly with their home mountain and favorite parks without having to sift through the clutter of social media feeds with baby pictures and selfies,” Wypler said in a statement.

When they were younger, DiLullo and Wypler would ride street and dirt jumps. Then, when they were teenagers, Mountain Creek Bike Park opened in Vernon, and they made the park their home-base. DiLullo, who grew up in Harrington Park, now lives in Boulder, Colo. Wypler is from Ridgewood, and currently lives in Australia.

The app largely sprung from their mutual frustration with available information, but also their desire to give back to the biker community, DiLullo said.

“Mountain bikers, it almost seems, are inherently good people,” he said. “We’re just doing it for the love of mountain biking.”

The app is free and will launch Friday. For more information, follow Muddy Tyre on Facebook and Instagram (@Muddy_Tyre), or visit the app's website.