Swipe from left to go back

On iPhones, in most apps (and when browsing the web in safari) users can swipe from the left of the screen to go back to the previous page. The purpose is to make navigation faster and easier when using the phone one handed, as you don't need to reach to the top left back arrow. could Trolley add this to the iphone app? It would make navigating the app so much easier, especially when holding the phone one handed in the supermarket!