ST Call

ST Call is a convenient Chrome extension designed for SmarTone customers that enables WiFi calling to any Hong Kong number without incurring roaming charges. Users can make and receive calls globally using their regular mobile number, ensuring the recipient sees their usual caller ID. The service works even when mobile signals are weak or unavailable, making it ideal for staying connected both in Hong Kong and overseas.

Key features include voicemail with missed call alerts, call waiting, dual SIM and eSIM support, and seamless contact management by sharing your device's phone book. The app offers a simple user flow requiring only a WiFi connection and the ST Call app running in the background. Note that the service applies to designated SmarTone service plans and may incur data charges according to your plan.