After activating your account you need to log in to the web app.
For Outgoing calls-
Step 1: Login to the Callhippo-
Step 2: Click on to Open Dialer from the Web App and log in or you can directly login to the phone app with this URL: dialer.callhippo.com.
Step 3: Type the number you want to call and click on the call button.
For Incoming Calls-
Step 1: Your dialer should be open.
Step 2: When you will get an incoming call you will get a notification and your screen will be like this.
Step 3: After picking up the call your screen will look like this.