Flickr - image and video hosting website
Mail the Family - Send postcards to a group as easily as posting a tweet.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Moo Postcards - Simple postcard printing
PhotoPrism.app - PhotoPrism® is an AI-Powered Photos App for the Decentralized Web. It makes use of the latest technologies to tag and find pictures automatically without getting in your way. You can run it at home, on a private server, or in the cloud.
Mailform Postcards - Choose any photo and send it as a postcard!