Long checkout queues are a thing of the past at Amazon's new app-enabled store, which allows shoppers to simply walk out with their groceries.

The Amazon Go store in Seattle welcomed its first customers yesterday, 22 January 2018. This marked the debut of the company's sensor technology that detects items taken off the shelves and keeps track of them in a virtual shopping cart.

The sensors – similar to those used in self-driving vehicles – automatically notice when items are removed or put back on the shelves, in proximity to the shopper's smartphone.

Once they leave the store, a receipt is sent digitally and their Amazon account is billed.

"We created the world's most advanced shopping technology so you never have to wait in line," said a statement on Amazon's website. "With our Just Walk Out Shopping experience, simply use the Amazon Go app to enter the store, take the products you want, and go! No lines, no checkout."

The first store is located near the corner of Seventh Avenue and Blanchard Street, just north of Seattle's Downtown area. Covering 1,800 square feet, it offers ready-to-eat dishes, grocery essentials, snacks and meal kits.

Sales advisors are on hand to provide assistance and re-stack shelves, while on-site chefs prepare food and products fresh.

The Amazon Go app is compatible with recent iPhone and Android phones, and free to download. Once used to enter the store, the device can be put away while shopping.

"We asked ourselves: what if we could create a shopping experience with no lines and no checkout?" said Amazon. "Could we push the boundaries of computer vision and machine learning to create a store where customers could simply take what they want and go?"

The company is investing heavily in ways to enhance the retail experience for customers. It recently announced Amazon Key, which allows delivery people to enter a home and drop off a package while the customer is out.

Amazon is also experimenting with delivery drones, and has filed patents for ideas ranging from flying warehouses and underwater depots to a highway network designed to stop self-driving cars crashing.