The original design was done in Upverter, so you can modify it in your browser without installing any software:
Please note that this project uses an MCU that is only available in a fine pitch QFN which is not trivial to assemble. The previous B3 Blinking Business card Badge uses NFC EEPROM which are available in larger packages that are more friendly for beginners.
More recent revisions are done in KiCad and will be posted to github.
Nice! Make sure to put a QR code on it too. iPhones can't directly import a vcard via NFC. I started a little project like that a few years ago but in the end, dropped it because... Apple.