Happy Worldwide Free Card Day, iPhone users! What's that? You didn't know about this March 27 holiday? Sign into your Sincerely account  (the company behind Postagram and PopBooth) where you'll find 10 credits until midnight PST to send one free card with any of their partner apps through your iPhone or iPad.
The Sincerely partners are third-party photography apps that feature the "Send Postcard" button. It's a tough decision selecting just which photography app to use of the 20+ available in this promotion. We're liking the abstract randomized images from Decim8  ($1) and the bright colors of the Purikura-style Mr. Chiizu Plus app  (free). Which app will you use for your free card?