Each release of the app includes improvements and sometimes also bug fixes. Please keep in mind that each new version of the Alert App is optimized to work best with the latest firmware version.
Normally, you will receive a notification informing about an available update of the App, click on it and you will be redirected to the store to update it.
You can also check the App Store/Google Play Store to search for the latest update.
To check which version of the Alert App you're currently using go to the More tab in your Alert App and check the About section.