A pop-up notification on your right bottom of http://my.exotel.in page, when you receive a call. Read Know your customer for detailed info. Note that details of the caller like the name will be displayed only if they're saved in the Exotel Address book
Additionally, If you are an administrator(Admin) of your Exotel Account, then:
You can get mail about incoming calls that don't reach any group (Call attempt notification email) by adding an email applet at the end of the call flow.
You also get a notification email for the outbound call that you make from exotel dashboard.