After the download of application from Google Play or iOS market please use the QR code below. The SIP account will be set automatically, then fill in only your username and password. You can also visit Zoiper page.

QR image

You can also check the settings as shown below 

Account-Network Settings

Account Codecs

Connectivity

And on the "Listening ports" tab, set Local RTP Port to 10,000 (clear the Random Port setting)