I want an online interactive whiteboard used by two people at the same time, having drawing, messaging, and video chat features, file uploading such as pdf and working on it together. As long as it is web based, we are open to any platform. Lets say two people log in to the system, and they have the whiteboard on their screens, and they see each other through camera, talk to each other and at the same time chat with each other. While doing all of them, for example by using the whiteboard, they can work on a project by drawing or typing. I need an estimate for this project, we are very serious.