Daria Rebenok had moved from Spain to San Francisco to work on a startup, a virtual-reality organization tool called myWebRoom, with her husband, Artem Fedyaev. But there were a few things she missed about Spain.

Specifically, something she used to buy in her local grocery store: boxed cold gazpacho soup. She knew it was a little thing--a small, if very specific, craving. But if every grocery store in Spain had it, and for cheap, why couldn't she find it anywhere in the Bay Area? Or why couldn't she have it sent to her door?

The entrepreneur did not shrug her shoulders and sigh at the complex tapestry of global economics and international trade infrastructure that created such rich commerce in her new locale. After all, she could readily purchase a hot cup of rare coffee from beans hauled in a dinghy across the Red Sea by a Yemeni kidnapping escapee ($16 from Blue Bottle). Or foie gras ice cream ($3.25 per scoop at Humphry Slocombe). But what good did it do her if she couldn't buy a single damn chilled box of gazpacho?

She did not turn away from her problem. She addressed it. And not by buying a round-trip ticket to Barcelona.

She built an app.

It's called Grabr, and it launched officially, after roughly a year of brand-building, venture-capital collecting, and beta-testing, on July 19.

Grabr is an in-app marketplace, where an individual who wants something they can't find locally can post their plea for another human to bring it to them--for a fee those individuals decide, which generally ranges from $5 to $20. (Grabr takes a 7 percent cut of such fees.) And today, individuals are connecting to facilitate the movement of lots of individual things around the globe--in late July, a DJI Phantom 4 drone was wanted in Moscow;  a small bottle of Clinique foundation was desired in Sao Paolo.

On Grabr's website, the suggested categories of items to request include unique cultural items (say, macarons from a particular French café), items "not sold where you live" (say, a British tea in Costa Rica), or items expensive to ship (say, golf clubs from the United States to Hong Kong).

There, of course, are exceptions.

"We are definitely not facilitating transactions where prohibited goods are being brought into countries. No guns, no porn. Nothing sharp," says Rebenok, who's originally from Russia. "We suggest not to bring any alcohol into certain Muslim countries."

In Grabr's terms of service, the list of prohibited items includes illegal drugs, human remains, counterfeit currency, and live animals. Items imported without a customs declaration are banned; stolen property or anything the U.S. government deems hazardous are also no-gos.

How can a tech startup built to scale actively and effectively police its users? It's not an easy question. Companies designed as peer-to-peer marketplaces, a la Airbnb and Grabr, say they're simply facilitating person-to-person connection via technology. This lets those people, not the company, make the arrangements, which allows the company to wipe its hands clean of culpability. (Or at least that's part of the idea.)

As for Grabr, now that it's opened itself up to a general audience, it still has staff monitoring the requests and transactions flowing through its site. Concerns regarding Grabr's being used for illegal activity, Rebenok says, are "why it's a semi-manual, semi-automatic system. We have people monitoring for compliance."

What about medicine, vitamins, and counterfeit items? What about items for which a company has exclusive import-export rights? Items barred from trade due to sanctions?  What about avoiding the taxes that may differ wildly from jurisdiction to jurisdiction?

"I could imagine a scenario where, on this site, people are looking to get cheaper goods for a good price. And with that comes copyright. And trademark infringements," should goods be counterfeit, says Gregory Miller, an attorney specializing in commerce and intellectual property law at the New York-based Rivkin Radler. "That'll be a necessary thing to address here."

It does seem that the traveler paying a typical customs-duty rate would cover tax in the United States, for the most part. Still questions persist--but, when pressed on the issue of whether goods were being transported illegally across borders thanks to Grabr, Rebenok says: "We are not doing anything illegal. Absolutely not." 

Grabr, which is now funded with $1 million and employs 22 people in San Francisco and Moscow, certainly has its work cut out for it to ensure that that remains the case.

There is something resembling a competitor--Airmule, which seeks to monetize the extra inches in your suitcase. It is another person-to-person marketplace--only it starts with the traveler, who can list on an app their empty suitcase space and their trip itinerary. (The space goes for about $10 per pound, and the company provides rigorous user-identification--and insurance against loss or damage up to $200.)

Currently, Grabr is open for business--and is hoping to complete another rounding of funding in the coming months, betting that investors will see the potential in its marketplace and another appealing portion of the business: Data.

Popular categories of goods being requested and purchased from around the world are becoming clear on the platform. Electronics, watches, shoes, and cosmetics are all popular. Protein powder, weirdly enough, is too. Eventually, patterns about specific goods that could be imported or sold more efficiently may emerge as well.

"Companies can spend millions on predicting what countries to sell in. They want to know: What products should we sell there?" Rebenok says. "We already know."