Announced back in October of 2011 alonsgside the iPhone 4S as an easy way create and mail custom letterpress cards personalized with your own text and photos, the Cards app for iOS has been sent to the shredder. Apple Knowledge Base:
Cards ordered before 1 PM Pacific time on September 10, 2013, will be delivered, and push notifications will continue to work.
You can view your previous purchases by tapping Saved Cards in the app.
Note: You can still order beautiful letterpress cards customized with your photos and text using iPhoto on your Mac. Cards ordered through iPhoto are shipped through a carrier such as FedEx rather than through the United States Post Office.
Several years ago Apple end-of-lifed their Texas Hold'em game for iOS, so this is not unprecedented. Having used Cards in the past myself, I have to say the service offered by Apple was a bit better than that of others available in the App Store but I don't see it as massive loss in any case. Based on the email we're being sent, however, some of you will clearly miss it. Anyone out there have a favorite alternative, iPhoto or otherwise?
Source: Apple Knowledge base