This app plays a loud SMS tone, using the ringer volume.
This fikses a bug on Android devices where original SMS tone is played using the media volume.
This is is especially usefull wuth bluetooth in car, headphone and headsets.
The tone from this app is played two seconda after your original sms app tone.

If the app suddenly stops working, this can be fixed in Android Battery settings.
See Android settings->Battery->App-startup. Select Administer manualy for this app.

For now, only Google Messages SMS app is supported.
App selection may be added in future if users want it.