Can I use SignalR in Xamarin.Forms for sending/receiving notifications? For example, can I send notifications to a server or receive notifications through Xamarin.Forms?
If you mean making the app able to receive notifications even if it's not running, consider using platform Push Notification or a wrapper that provide one Api for all platforms, like OneSignal
SignalR is intended to solve diffident problem, it uses Websocket with a possible fallback to Server Sent Events or Long Polling to implement Real-Time communication with the server, witch is suitable for Chatting App as an example