I've been using Postagram (https://sincerely.com/postagram https://sincerely.com/postagram) for a few years to send a card to my grandmother regularly from my s

I've been using Postagram (https://sincerely.com/postagram https://sincerely.com/postagram) for a few years to send a card to my grandmother regularly from my smartphone. The cards look great, cost $1, and have the image in a perforated square which can be punched out of the card, with the description on the back. They have a solid app with tracking and history. Hard to beat that, but maybe the feature that Simple Postcard has is fitting the image to a 4x6 area (full front of the card) rather than the smaller square (3x3", I think) on the Postagrams.