SMSDefender

The best and simplest way to filter out spam SMS messages! Quickly set up easy to understand rules for the messages you don't want to get notified about.
After setting up your rules, to enable SMSDefender:
• Go to Settings -> Messages -> Unknown & Spam
• Then enable Filter Unknown Senders
• Then select SMSDefender and choose Enable
NOTE: rules will only run against unknown numbers
The benefits of using SMSDefender:
• Small app with no bloat.
• No data gets sent or requested from any server.
• Complete privacy.
• All of your data is local.
• Syncing of your rules to your iCloud profile.
• Trusted app from a trusted software development company.