To change the search to a round ticket, which means "there and back", press on "Round trip" in the middle
The search is initially set to a one-way ticket. You can also change it to "Multi-city". That option will search for non-direct routes where you change flights, which allows you to find a cheaper ticket, prolong your flight, or find the only option available.
As you can see now, it is giving you a promotional deal at the top, which is not necessarily going to be the best price. Instead, the default search lists the lowest price deals first. In this case, it is Norwegian Airlines with a flight that costs only £248, which is quite cheap to get to New York from London.
You have been watching VisiHow! I have just shown you how to search flights with the Kayak application on the iPhone 6. If you have any questions or comments, please put them in the section below. Thank you for watching!