Instacart announced it would expand its mobile app-based Instacart Pickup grocery pickup and delivery service to retailers nationwide, according to a company release. The service allows customers to pay for groceries and tip drivers using a mobile device.

The San Francisco-based mobile delivery provider comes after a pilot program were got feedback from customers on its grocery delivery service. As a result, Instacart officials said the company deepened its relationship with grocery chains including Aldi, Cub Foods, Food Lion, Price Chopper, Publix, Schnucks, Smart & Final, Sprouts, Tops Friendly Markets and Wegmans.

The expanded coverage area includes about 200 stores in  25 key U.S. markets in major metropolitan areas around Atlanta, Boston, Charlotte, Minneapolis, Nashville, San Francisco and Washington D.C.

Customers can place orders online at  www.instacart.com or use the Instacart mobile app, select a city and store, add groceries and then choose a delivery or pickup window, before checking out. Customers will receive an in-app notification, while pickup customers can then send a notification to the Instacart personal shopper alerting them that they are headed for the retail location.

Aldi announced a pilot program with Instacart in September 2017 that followed Amazon's acquistion of Whole Foods and ramped up competition for grocery delivery with Walmart and other retailers.