The app filters incoming calls and SMSes from unknown contacts, including overseas numbers. ScamShield uses a combination of an on-device algorithm and information provided by the Singapore Police Force (SPF), such as blacklisted numbers linked to scams, to determine if a call or SMS is a scam or not.
When you receive an incoming SMS from an unknown contact, ScamShield will determine if the SMS is a scam using an on-device algorithm. For iOS, it filters the messages to a junk SMS folder. For Android, a notification is sent to users to notify them that a scam message has been received.
Scam calls and SMSes detected by the algorithm or reported by the public will be sent to National Crime Prevention Council (NCPC) and SPF for collation. This keeps the app updated and will help protect others from such scam calls and messages. For your privacy, ScamShield does not filter calls and SMSes coming from a contact known to you.
Let other citizens know if this answer was helpful 
in