Ever wish you had your own private dog park? This app lets you rent one.

Dogs show up in Tracy Johnson’s Roxborough backyard at least once a week.

With their humans in tow, the pups run around for an hour or more, enjoying the fenced-in space they don’t have at home.

These tail-waggers aren’t trespassers. In fact, their owners pay Johnson $15 per dog per hour to use her yard as a private dog park.

“I love dogs,” Johnson said. And she loves that her place can be a haven for “dogs that are afraid of other dogs or afraid of other people,” whose owners may not want to frequent the region’s many free dog parks.

Johnson rents out her yard through an app called Sniffspot, which describes itself as “like Airbnb, but for off-leash dog spaces.”

Founder and CEO David Adams started the company in the Seattle area in 2018, and it grew organically across the country. Its popularity increased during the pandemic, as more people adopted pets and some cities like Washington, D.C., temporarily closed their public dog parks.

The West Coast remains Sniffspot’s largest area, bringing in about a third of the company’s business, according to Adams. But on the East Coast, he said, the Philadelphia region is paw-ticularly active, with about 600 hosts offering their outdoor spaces.

“Our top hosts are getting hundreds of visits every month,” said Adams, who now lives in Massachusetts. “They are basically fully booked for all daylight hours.”

Sniffspot hosts set their own prices, charging $10 per dog per hour on average, Adams said. Larger spaces with more amenities, such as tennis balls, ball chuckers, and water for dogs and humans, command higher rates. Yards over half an acre in size tend to have more visitors, he said.

“People love going to places where their dogs can really run,” Adams said. At some spots, “hosts have turned them into dog Disneylands.”

Sniffspot typically takes 25% of a site’s earnings, Adams said. The top hosts take home over $3,000 a month, Adams said.

One North Philadelphia resident, who asked to remain anonymous to speak openly about his Sniffspot earnings, said he’s made about $10,000 in two years.

As of last week, Johnson said she had made $734 in the year-and-a-half she’s been renting her yard on Sniffspot.

“It’s small cash,” said Johnson, who also runs a dog-boarding facility and pet service company called Two Dog People. But it’s “little work,” aside from keeping the yard clean and free from any potential hazards.

“It’s different from a lot of other side hustles,” Adams said. “You can just let people use your yard.”

Hosts don’t even need to be home during visits, Adams said, as guests receive self-service entry instructions. The experience is designed to be private, he added, with most guests never meeting their hosts. Any dogs who live at the home stay inside during reservations.

For potential Sniffspot guests, the app is free to download. To book, they must sign up for a seven-day free trial, which includes a $10 credit and discounts on some spots. After that, users must pay up front each month, between $20 and $120, which goes toward bookings.

Sully Carlin arrived at the Sniffspot with his snoot to the ground.

The 4-year-old black lab mix has his own backyard, so he was a bit confused as to why his humans were leading him through a stranger’s gate, with no stranger in sight.

But then he saw the two-acre property — and took off. He attempted to sniff every blade of grass. He chased tennis balls at a full sprint. Soon, he was panting, his long tongue hanging down so far it threatened to fall right out of his mouth. He sauntered over to a metal bowl and lapped up a couple ounces of water, then looked up with tired eyes.

It had only been 20 minutes, and the humans had reserved the space for an hour, but Sully was ready to go. As he ambled to the car, he was too exhausted to comment.

So went my own experience at a South Jersey Sniffspot earlier this week.

Walking onto someone else’s property felt a bit strange, even though we exchanged messages in advance (and I told the host I am a reporter). Once inside, however, it was easy to see the appeal, especially for people and pups who don’t have fenced-in yards at home.

About 90% of Sniffspot guests fall into that category, Adams said.

Dog trainers also rent hosts’ yards for private sessions, he said, while animal shelters use them as neutral sites for rescue dogs to meet their potential adopters’ existing pups. Organizers of local dog groups sometimes host breed-specific meetups at Sniffspots.

And, of course, there are dog birthday parties.

Johnson has hosted several such celebrations, welcoming up to 12 dogs at a time, plus their humans. Humans can add a customized birthday sign to any visit for $5.

“When they rent the birthday sign, I give them party hats and blowers,” Johnson said, plus “fun leis and scarves so they can do a photo-op.”

Johnson also offers to come outside during parties to coordinate games and races for the birthday pup and friends.

These personal touches attract loyal guests, who increasingly want to pamper their dogs, Adams said. Just a few decades ago, dogs were usually outdoor pets, he noted, but times have changed.

“Now people have their dogs sleeping in their beds,” he said. “They are realizing that dogs need to be taken care of more than they have in the past.”