Emily Watson is that friend whose kitchen is always spotless and whose elaborate homemade meals appear effortless.

"I've always cooked for family and friends," Watson, 30, of the city's Graduate Hospital section, said as she pulsed miso, cilantro, ginger, and garlic in a food processor. "I just haven't gotten paid for it ever."

Now, that's changed, thanks to an app called Homemade that arrived last month in Philadelphia.

It's among a number of so-called food-sharing apps and websites aiming to disrupt the restaurant industry much as Uber has for taxicabs and Airbnb has for lodging. They're connecting home cooks to paying customers for takeout, delivery, or dine-in meals, ranging from dinners for one to supper clubs for 24.

Homemade and a competitor, Local Stove, launched last week by three Wharton alumni, are hoping diners will be hungry enough to venture into the uncharted territory of strangers' kitchens - and that regulators will be too busy to cite the unlicensed and potentially illegal ventures.

City officials call it a public-health concern. But the developers say it's an answer to meager restaurant wages and an innovative way to bring healthy meals into food deserts.

Homemade chief executive Nick Devane said the concept might sound odd at first. But many users, like Watson, are already cooking for friends or neighbors.

"If they're already sharing food," he said, "we're just solving a pain point - of cash handoff and ordering."

But the app could expand sales beyond a person's own network and turn a sideline into a profitable cottage industry.

That's the idea for Julia Erlichman, 55, of Bella Vista, who for the last year has cooked weeknight dinners for four of her friends and their families.

"They're busy mothers who don't have time to cook, or don't like to cook, or aren't good cooks," she said, "but would like to provide their families with a nice, home-cooked meal."

She doesn't have formal culinary training. But, then, hers is adamantly not restaurant-style food. Think beef with broccoli over fried rice, or oven-crisp chicken with honey mustard sauce, roasted potatoes, and asparagus, for about $11 a plate.

Devane said about 30 cooks from greater Philadelphia had signed up. In the New York area, Homemade has about 150 active cooks. More than half, he said, have professional training as chefs, dietitians, or caterers. He thinks a skilled chef could make more online than on the line, even after Homemade's 9 percent fee.

Some of the most successful cooks, he added, are in food deserts.

Watson, who does business under the name of her blog, Nourishing-Matters.com, plans to offer meals once or twice a week, targeting those who are tired of fast-casual takeout but who can't afford a private chef.

On a recent evening, she'd sold five dinners: soba noodles with roasted cauliflower and miso-cilantro dressing, sprinkled with toasted almonds, and portioned into kraft-paper takeout containers.

Chris Wetzel, 30, and his wife, Katie, 29, friends of Watson's who live nearby, stopped over to pick up their meals, $12 apiece. They rarely have time to cook, Chris said. "And when we do, it's not that great."

It was a healthier, comparably priced alternative to takeout, he said.

Soon, there may be even more options.

Henrique Setton, a cofounder of Local Stove, said more than 100 cooks in Philadelphia had expressed interest in his website, which is in a beta phase. He and his partners took it on a two-week test run last year, marketing to Wharton students. They sold 130 meals, converting 40 percent of diners into repeat customers. It seemed like a hit.

Now, Setton said, the Local Stove team will be experimenting with focusing on different types of food and modes of delivery. To start, it's pickup only, to foster relationships between chefs and eaters.

"We're trying to build a community around food," he said.

The same idea drives users of sites like Eatwith, Feastly, and Meal Sharing, which enable hosts to invite paying dinner guests into their homes.

Arielle Tannenbaum, 27, and Rachel Sakoff, 30, joined Eatwith last year and host bimonthly dinners for eight to 10 guests at Sakoff's apartment in Bella Vista. Sakoff is a dietitian, and both women are interested in healthy cooking. For $43, they serve a four-course meal, starting with butternut squash bisque, maybe, or a roasted grapefruit salad.

Guests have included tourists, a family celebrating a birthday, and friends of friends. "It's people wanting to learn about healthy food, meet new people, and feel a little inspired," Tannenbaum said.

For others, the sites represent a chance to fulfill dreams of breaking into the restaurant industry - without the relentless hours and financial risk.

That's what hooked Ryan Fitzgerald, 29, who runs Boku Supper Club, a monthly dinner for 24 that ranges from Italian Sunday supper to six courses of molecular gastronomy.

He started a year ago via Feastly but recently began booking through his own website. The fees are lower, and he can set his own cancellation policy, which is crucial, given how much he spends on ingredients. He has a 500-person email list and usually sells out within an hour.

Fitzgerald said guests pay the up-to-$65 admission fee for his art exhibition; the multicourse meal is complimentary.

After all, none of these food-sharing apps asks for training or experience, or demands the food-safety certifications required in Philadelphia for even the humblest of falafel carts. The home kitchens are generally not licensed for commercial use by the city Department of Licenses and Inspections, and so are not inspected by the Department of Health.

L&I likely could issue violations or cease-operations orders in these cases, spokeswoman Karen Guss said. Inspectors might not be swayed by a claim that guests are paying to see art, not to eat, or by arguments that customers aren't paying, but are making donations.

"Inspectors would enforce on a case-by-case basis," she said, "and it's likely that the entrepreneur would, at some point, have to make their argument to a judge."

Cooks are betting that L&I won't get around to it, though. As Watson said, "I'll do it until someone tells me to stop."

In the meantime, apps and websites generally post lengthy user agreements noting that they are platforms - not food providers - and aren't liable.

Devane thinks that food-sharing is here to stay - and that regulators need to catch up.

"It's already happening: People sell food through hacking [delivery sites like] Seamless or via Instagram," he said. "We now trust to stay in a stranger's home or get in a stranger's car. There's a societal shift."