Apple’s Cards app introduced in 2011 and discontinued two years later remains one of my favorite iPhone apps to date. The service was fantastic: snap photos on your iPhone, then turn then into personalized letterpress cards sent through the mail to friends and family. Stamp and envelope included, you’d pay $2.99 for anywhere in the US or $4.99 for anywhere around the world. You can still send personalized letterpress cards using Photos on the Mac, but the service was perfect for me as an iPhone app.
I’ve tried a handful of similar iPhone apps since Cards shut down with Postly being the latest and perhaps most modern. Available for iPhone and iPad, Postly lets you create personalized postcards from your iPhone that deliver worldwide for $1.99.