Health checks in Casa App allow you to verify the health of a key without actually having to send any BTC from your keyset.
To perform a health check with Keystone, first, tap the hardware device icon from the main app screen, then tap "Perform Health Check."
Casa App will then provide you with a QR code which you will need to scan from your Keystone device. On your Keystone device, select "Multisig Wallet" from the main sidebar menu on the left, then select "Perform Health Check."
On the next screen, select the scanner option at the top right-hand side of the screen to open your Keystone's camera, then scan the QR code shown to you in Casa App.
You will need to enter your Keystone's password to confirm the signature.
Once you scan the QR code using your Keystone device, there's still another important step.
Using Casa App on your mobile phone, scan the QR code that is shown on your Keystone device.
That's it! You've now performed a health check with your Keystone device. You know that it's standing by and ready to sign a Bitcoin transaction when needed.