The coffee chain is expanding its mobile ordering service to locations in Rhode Island and Massachusetts, including nine Boston stores, according to the Boston Herald. The app helps customers avoid long lines, particularly in the morning, but it’s only available for DD Perks rewards members with iOS phones.

As Fortune previously reported, the app originally launched in November as Dunkin’ Donuts (DNKN) began testing it at 125 locations around Portland, Maine. The company’s vice president of global consumer engagement, Scott Hudler, told the Boston Herald, “We’ve been really pleased with what we’re seeing.” He added that as “usage continues to rise,” Dunkin’ Donuts wants to test the app in Boston to collect “more robust consumer data” before launching on-the-go ordering nationally later this year.

Using the app, customers can place orders 24 hours in advance. When they’re close by, they click “Ready to Pick Up” and their order should be waiting for them either in the store or at the drive-thru window.

Dunkin Donuts, which had a surprising drop in sales in the last quarter of 2015, is hoping that the Dunkin VIP app will help it better compete against Starbucks (SBUX), which launched mobile ordering in September of last year.