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.
Giftagram - Discover and deliver gifts easily through an app
The Simple Postcard - Text a photo to mail it as a postcard
Tremendous - Tremendous is a customer and employee loyalty platform that allows companies to reward their customers for surveys promotions and referrals.
Felt for iPhone - Handwritten cards for the modern world
Patreon - Patreon enables fans to give ongoing support to their favorite creators.