Postsnap - Postsnap's iPhone app is the best, free postcard creator. Make & send real printed postcards, greeting cards, invitations and announcement cards using your own photos.
Stampix - Photo printing in a fast, easy & ecological way.
The Simple Postcard - Text a photo to mail it as a postcard
Felt for iPhone - Handwritten cards for the modern world
Postalie - We help people connect with their loved ones by sending real postcards or letters to anybody, anywhere. Worldwide delivery. Private and Secured.
Handwrytten - Handwritten notes straight from your device. Huge selection of cards or design your own. Handwriting service integrates with 1000's of apps.