What are Washingtonians apt to ask for when they can use a smartphone app that fulfills grocery orders? Produce and alcohol. Lots of alcohol.

“Alcohol has been a big part of it,” said Aditya Shah, the head of expansion at Instacart, an app that delivers groceries from local stores to your doorstep in as little as an hour.

Instacart is now expanding its geographic footprint locally and adding Safeway to the roster of stores from which it will fill orders, Shah said.

The app debuted in the Washington region in February. Though Shah declined to specify how many people use the app or how many deliveries have been completed, he said it has proven popular among busy young professionals and college students.

Instacart’s new territory includes a broader swath of Maryland and Northern Virginia, including Takoma Park, Chevy Chase, Silver Spring, Bethesda, Alexandria, Arlington and McLean.

The push into the suburbs is unique as similar applications, such as Washio for dirty laundry or Uber for car sharing, don’t venture far from places where a concentration of car-less people with disposable income live.

Still, Shah said Instacart sees an opportunity to serve more suburban customers and intends to keep its commitment of delivering orders in as little as an hour, often for an extra fee.

At the time of its launch, orders could only be filled at Harris Teeter stores. The inclusion of Safeway comes after Whole Foods and Costco were added to the app in recent weeks.

Costco, in particular, has been a draw for college students and offices looking to buy food in bulk, Shah said.

“A lot of the offices do weekly runs with Instacart, so we’ll see large orders consisting of 300 cans of Coca-Cola or 50 bananas,” Shah said. “We know those are offices that are stocking up.”

Follow reporter Steven Overly on Twitter: @StevenOverly