Ask any devices or smart home question in the Devices/Security or Network Troubleshooting Categories.
When I download and try to install the desktop app on my iMac it thinks the app is damaged
"The app has been modified, and its code does not match the original signed code. The app may be broken or corrupted, or it may have been tampered with. If you think that an app has been damaged or tampered with, you should delete it by dragging it to the Trash.
To learn how to protect your Mac from harmful software, see Protect your Mac from malware."