Just a reminder.
The UK government will broadcast an Emergency Alert Mobile Phone Test at
3pm today 23/04
This will be on all compatible mobile phones and tablets and you should hear it even if your device is on silent, you should hear a loud siren sound and vibration for 10 seconds and a message displayed on the home screen, however although it's not recommended you do have the ability to disable Emergency Alerts in your devices settings, this maybe something you wish to do if you're driving during the test.
https://www.bbc.co.uk/news/uk-65177316
https://www.gov.uk/alerts