Create Invitation Cards To Keep. Some invitation cards are so special that you’ll want to keep them forever. HappyCard enables you to create this kind of cards yourself using only a few clicks.HappyCard helps users with its simple to use interface to create invitation cards with just a few clicks. Creatively done cards, without any previous knowledge. No matter if you want to do an invitation card, a greeting card or a gift card: HappyCard comes with 50 professional card designs for events like birthdays, parties, weddings, condolence-cards, etc.