Canva

Canva is a versatile online graphic design platform that allows users to create a wide range of visual content, including greeting cards and eCards. It offers a user-friendly drag-and-drop interface, a vast library of templates and design elements, and features for collaboration and sharing. Users can personalize designs with text, images, and other media, and save their creations within their accounts.

Canva offers a robust online design platform that includes a dedicated section for creating various types of cards, including group greeting cards and eCards. It provides an extensive library of templates, a drag-and-drop editor for personalization with text, photos, stickers, and GIFs, and options for sharing via link or social media. Users can create accounts to save their designs and collaborate in real-time. While it doesn't explicitly mention animated envelope reveals or music for e-cards on the provided pages, its core functionality aligns very well with the must-have features and several other features of GreetsU.