The synchronization keeps your lists up-to-date across multiple devices. In addition, you can create groups for different events, create multiple lists per group and invite multiple members. E.g. for family, roommates, office, wedding, vacation, party planning, etc. To briefly clarify, each group has its own chat with picture and text messages. Helpful if you don't know which shampoo to buy? Or who will bring the barbecue charcoal after Max has cancelled at short notice? With the group chat