When retired Chicago Bears linebacker Hunter Hillenmeyer launched OverDog earlier this year, he had about $100,000 raised from a Kickstarter campaign and the commitment from dozens of athletes from his connections in the NFL and other relentless networking. More importantly, he had an inkling that fans might get into the chance to play video games against some of their favorite athletes and break a separation between sports stars and their fans.

First released an an iOS app, Overdog became available for Android on Monday. The iOS app was a hit, rising quickly in popularity and succeeding, so far, in Hillenmeyer's vision of athletes interacting with fans while doing something that they would probably be doing anyway.

"There was a million different little tiny things that we wanted to improve on (from the initial launch),” said Hillenmeyer in a phone interview Monday.

Through the app, which fans can download on their mobile devices to play on PlayStation or XBox, fans can sign up to challenge more than 200 athletes from the NFL, NBA, MLB, UFC, WWE, MLS and more in video games. The app, which is an NFLPA licensee, is concentrating on NFL players during the fall, said Hillenmeyer.

"I think part of the beauty of OverDog is we've found a way to build a great experience for athletes based on existing behavior," he said. "A lot of these guys go home and play hours of video games every night so we’re not trying to get them to do something they’re not already doing."

On Twitter, numerous athletes including David Price (who is on the company's advisory board), Ray Rice, Matt Forte, Calvin Johnson, Charles "Peanut" Tillman and Steven Holcomb, the Olympic gold medalist in bobsledding, are among those who have plugged the app and actually taken on fans. Some of those athletes, Hillenmeyer said, have written to him to express how cool the experience was.

So how competitive do people like the Ravens' running back get when playing against random strangers? “Ray [Rice] really cares whether he wins the game or not but so do the fans," Hillenmeyer said. "So obviously Ray is a better football player than any fan he’s going to play against but when you get the controller in their hands it's kind of an equalizer …

"That's part of the fun."

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