Desktop video calling application prototype

We need a prototype of a desktop video calling application for Windows and macOS platforms. The application should be built using Electron framework, because we’ll need to add more functions to it from our existing web application in the future. Functional requirements: - Add functionality from our existing web application: - Chat system - Video calls (with screen sharing), we use Voxeet SDK. - Annotation system: when a screen sharing is enabled, call participants should be able to draw over the shared screen. All participants should see all drawings. We already have similar functionality (drawing on a shared virtual whiteboard) in our web application implemented. - “Always-on-top” option for an application window - User authentication The detailed application specifications, all necessary API documentation and designs will be provided. The developers who created chats (and other functions available in the web app) will be available for consulting to help with integration. If the prototype development will be a success, we can continue the work to develop the full application. We’re waiting for questions and estimations of time and costs to develop this prototype.