Softcard is a mobile wallet payment system that uses NFC technology.
In order to add American Express cards to Softcard, you have to log in to your American Express account from the Softcard app. This limits how many cards you can add because you are only allowed to add cards from one account. However, there is a workaround.
Once you have made a purchase on your card, go to americanexpress.com/softcardremoval and remove each of your American Express cards from Softcard, now you will be able to log in to a new American Express account from Softcard and add those new cards for more free gift cards.
Hurry, this will only last until the end of the month. I have already been emailed some Amazon Gift Cards for my first purchases.