No. The goal of Knowee is to facilitate card exchange, communication, and contact. Each Knowee business card is a webpage, so no application, software, download, or registration is required to view and use a received Knowee card. You can be sure that when you hand over your card, the recipient will be able to view it seamlessly on any device, as Knowee cards are fully responsive.
However, in the enterprise plan, you have access to a native app for iOS and Android that allows you to carry your cards and cardholder with you, and most importantly, scan paper business cards received.