WASHINGTON—I’ve always had anxiety about getting into a cab with only a credit card in hand for fear that I’d be scolded by the cab driver for not having cash. So Uber has become my go-to choice for getting from place to place in the nation’s capital.

This week when I pulled up my Uber account on my phone to request a ride, I learned that the service wasn’t only putting a kibosh on my anxiety, but now can also spare me the time I it takes for me to go to CVS or Walgreens.

Uber is a mobile app that connects company-approved drivers with passengers and allows them to pay a flat rate through their Uber account. Uber’s service is offered in dozens of American cities and 43 other countries.

And it is evolving. On Tuesday, Uber started an experimental delivery service in D.C., called Corner Store. The service will deliver almost anything found in drugstores, such as CVS or Rite Aid in less than 10 minutes.

Corner Store is available on week days between 9 a.m. and 9 p.m. D.C. shoppers can choose among the 100 items Uber has listed on an inventory list.

Not to mention, it’s free, at least for now. During the experimental phase, the user will only be charged for the cost of the item or items purchased — no cost for delivery or need to tip. Similar to the way customers are charged for an Uber ride, the items purchased will be charged to the user’s account.

“We’re excited to share one more experiment from the Uber Garage and offer D.C. users a seamless and convenient way to get their every-day items at the touch of a button,” Uber spokesman Taylor Bennett said in an email. “We’ve already seen an incredible response to Uber Corner Store and look forward to meeting the growing demand.”

Uber Garage is the San Franciso-based company’s branch that cooks up new and experimental services.

UberPool is another service housed in the Uber Garage. Through UberPool, users can split the fare cost of a ride with another person if they plan on traveling the same route. UberPool automatically finds you a match, in which the user can accept or deny the shared ride. The program is still in the beta testing phase.

Would I use the Corner Store service? If by some miracle it continues for free, then of course. Barring that unlikely event, I won’t break my ties with Postmates, a delivery service that can bring you anything from grocery store goods to school supplies for a relatively modest delivery fee.

It’s not a smooth ride for Uber, however. As the five-year-old company expands and develops its services, traditional taxicab companies are fighting back.

The most recent case in the Washington area focuses on antitrust issues. Nearly 30 cab companies in suburban Maryland communities are claiming Uber violates antitrust laws by fixing pricing for transportation.

But Ted Hassi, an antitrust attorney with O’Melveny & Myers LLP, said when you think about antitrust, it’s about protecting consumers.

“I think it’s a smart move on Uber’s part,” Hassi said. “What Uber is offering here is an innovative service that was not available in the marketplace before, it’s providing a benefit to consumers that taxicabs, for example, don’t offer.”

For now, the growth and experimental services continue for Uber.

Corner Store will run exclusively in D.C. for a few more weeks and will expand to other cities depending on how well it does.