Possibly works?
Copied and pasted a spam block message into their filtering system every 30 ish minutes I got a spam text from outlook. I never got one again?
Not enough ratings yet to assess SpamGuard.
SpamGuard: Spam Text Blocker appears legitimate, with a few gaps. AppsHunter Legitimacy Score for SpamGuard is 75/100.
Based on 75 of 100 points across 7 verification signals from App Store and developer data.