Create your own digital greeting cards - for designers, artists, and creators

It came from an idea my sister had. She creates handmade greeting cards for people, and wanted to digitize them. However, there were two problems:

• Flat ecards, which can be customized on some sites, are boring.
• Punchbowl's card animations are cool, but the cards can't really be customized.

Cards should be personal, fun to open, and easy to send. Being a web developer, I thought about creating a web app that would allow anyone to upload their designs and convert it into digital greeting cards (with click-and-open animations) to send. (Possible future features include a way for creators to make money from cards, public/private cards, etc.)

What do you think? Any ideas, suggestions, or are there any products that already do this? (I couldn't find any.)

You can check out the current animation at https://sponge-nifty-judo.glitch.me/. ;) Yes, the bold colors on the card look awful, but they're just waiting to be filled with creative designs...