Former NHL defenseman Brendan Witt admits he's not much of a tech guy.

The long-haired, tattooed Saskatchewan native looks more mountain-man-meets-motorcycle enthusiast than he does Silicon Valley entrepreneur.

Witt is both rugged -- in 2009, he was hit by a SUV while crossing the street one morning in Philadelphia and played a game later that night -- and unconventional -- he spurned a posh lifestyle of golf and beaches on Long Island's shore to move to a ranch in rural Montana after his retirement in 2010, opting for a simpler existence for his wife, Salima, and their two daughters.

But the 39-year-old Witt, who relished the charity work he used to do in conjunction with local children's hospitals during his playing days, wanted to find a way to still help those in need.

"The last two years of my brother's life, the pictures we have ... most of those were memories we had from those games," Jimmy McGowan said of Brendan Witt's "Witter's Hitters" program, which helped give him memories with his brother John. Courtesy McGowan family

During his playing days for the Washington Capitals and New York Islanders, Brendan and Salima developed an idea called "Witter's Hitters" as a way to provide families an escape from everyday life at a hospital. They'd treat their guests to a fun night out at an Isles or Caps game, providing them with tickets and team swag, along with VIP passes to meet players afterward.

Even after hanging up his skates and moving west, Witt remained in close contact with several of the families. And so it was fitting that it was Jimmy McGowan who helped Witt hatch the idea for the Angel Mail App, introduced this month and unveiled by Brendan in collaboration with Children's National Medical Center in Washington, D.C., earlier this week.

McGowan, now 28, met Witt in 1997 when he and his older brother John were both battling cystic fibrosis. The Witts visited them in the hospital, took them to Capitals games and gave them the star treatment. It wasn't a one-time thing, but rather a relationship. It's something that Jimmy appreciates much more, now that almost 15 years have passed since John passed away at the age of 16.

"The last two years of my brother's life, the pictures we have, the memories we have, the stories we would tell, most of those were memories we had from those games," McGowan told ESPN.com by phone Thursday afternoon.

McGowan, who now lives in Baltimore and is planning to become a special-education teacher, realizes just how precious of a gift was given to his entire family.

"He gave us memories," McGowan said of Witt. "Which is pretty priceless."

Witt knew that McGowan's family, like those of many others, spent long, grueling hours at the hospital. Things could be bleak, and he wanted to think of a way to lift the kids' spirits. But McGowan reminded Witt that sometimes the physical and emotional toll of medical treatment could leave patients feeling depleted. Even the thought of visitors could be exhausting.

So Brendan and Salima liked the idea of a smartphone app, one where a person could send a piece of mail -- a positive message, words of support, a prayer -- via customizable angel messenger that a kid could receive on his or her device. Witt wanted something both tangible, to provide comfort, and interactive, to make it personal.

Little did he know that developing an app was no easy process, requiring oodles of experience in technical jargon and computer code. He also didn't realize the sort of financial investment it would require; Brendan and Salima financed the $12,000 project themselves.

As such, Witt decided to donate part of the proceeds to Children's National and is using the remainder to further update the app so that it can eventually finance itself, with the next goal to make it available to Android users (it is now accessible for iPhones at the iTunes Store for 99 cents).

On Thursday, Witt went to the hospital where he spent many memorable visits during his days in D.C. He was happy to learn that some of the staffers and families still remembered him from his visits. Witt now appreciates the platform he had as an NHL player and the ease with which he was able to reach out during his playing days.

Kathy McGowan said the best thing you can do for the mother of a sick child is to bring a smile to her child's face. Courtesy of McGowan family

He hopes to continue that through his work with Angel Mail.

"All I want to hear is that it makes a difference in these kids' lives," Witt told ESPN.com Thursday.

Witt said both he and his wife loved being able to spend time with the families they met through "Witter's Hitter's" and that those efforts had a lasting impact on their own family.

"You see these kids and no matter what their background is, sickness preys on everybody," Witt said. "They are confined to rooms, they don't get to go out much, they don't get many visitors, so taking kids and letting them watch the game, to be able to see them come down after the game, whether we won or lost, and spend time signing autographs, it really makes their day. That was biggest thing I got out of it. I think it's important to give back to kids and give them life experiences [they] won't forget."

Kathy McGowan, mother to John, Jimmy and three other children with her husband, Jack, has never forgotten the moments of respite the Witts provided her family during what were their most difficult days.

"There's nothing better you can do for a mother of a chronically ill child other than when you see a smile on their face," said McGowan, who lives in Waldorf, Maryland. "When they are around their family and smiling, you take away the constant, everyday battle and it's fine for a while."

McGowan isn't at all surprised to see Brendan and Salima diving back into philanthropic work. Knowing what the two did for her own family, she expected as much.

"Once I met them and saw what they did and how important it was, I knew it would be a lifelong journey for them," McGowan said. "Someone that giving and caring isn't that way just for the moment. They're born that way. They have to continue to share like that. I knew they would continue."