tl;dr: Apple's short-lived Cards app (2011-2013), which let iPhone users design and mail letterpress cards, was personally initiated by Steve Jobs after a walk where he wished he could send a thank-you card from his phone. According to an anonymous source who ran the print program at Apple's fulfillment partner, the project (codenamed "Speed Racer") was a logistical nightmare involving 1850s Heidelberg letterpresses, invisible UV barcodes on envelopes, custom USPS heart stamps, and international print operations — only for launch-day demand to "fit in a shoebox." Jobs died the day after Cards was announced, and no one had the heart to kill it for two years.