SMS filter uses the new iOS 11 capability to filter SMS messages. SMS filter will filter SMS messages from unknown senders that contain words in a "junk words" list in the app. Messages marked as junk will not cause alerts on the phone and will be visible in a special junk tab in the messages app. All the filtering SMS filter performs is done on device, your privacy is protected and no message content is sent off the device.
SMS filter comes with a pre-built list of common words in spam message in the English language. You may edit this list, add your own words or remove words, and you can add words in any language. SMS filter also contains a list of words in Hebrew if your device contains that language.