For support, e-mail help@studentcenteredclassroomassistant.com (Yes, an odd name, but it’s me) – The instructions are on the home screen of the app. It may warn you that it will send text messages to me, I couldn’t find a way to tell (yet) the developer tools that I am not sending your messages over the network, everything stays on your device as far as my app/extension is concerned. Also, in messages settings, the app currently has no icon because I couldn’t figure out how to set an icon for that. The app does work, though, and will send messages keywords marked as blocked keywords to spam, unless allowed keywords allowed them.
This is a real simple app, it’s not pretty, it just (as far as I know) works, I threw it together in less than a day – though some polishing may be needed (some was given).
The Message filter is set by going to the system “Settings” app, going to the settings for the “Messages” app and looking under “Unknown & Spam” to find the setting.