The American company Amazon has launched a store that does not require you to stand in a checkout line or someone to process your payment. You simply need an app on a mobile device, such as a smartphone. People with the app can enter the store, choose the products they want and then leave the store with them. The company opened its first Amazon Go store this week in the state of Washington, after more than a year of testing. You first need to download the Amazon Go app, a computer program that helps you gain entry to the store. Once inside, hundreds of cameras and electronic sensors follow people’s movements and record all the products chosen. The products are then placed in the app’s virtual shopping cart. In other words, the app remembers everything chosen by the customer. If you decide against buying one or more products before leaving the store, the software automatically removes those items from its memory.