How does it work? When receiving a SMS or MMS, if its sender is not in your contacts, the app analyses its phone number and/or message content then filters it (or not) according to your criteria. Which criteria can be used? You can allow or block phone numbers and/or key words. For example, you can: -Block a message containing the key word "You win" -Allow a phone number starting with "5552" What happens with filtered messages? Notifications for Spam messages are disabled. And messages are sorted in the "SMS Junk" list of Messages App. How about User privacy? The app can access message content and its sender. But it cannot store anything on your device and cannot send anything.