Best answer by Ssherjj
Welcome to the Webroot Community,
At this time, there is not an antivirus option available for Apple iOS devices. Because of how Apple manages the apps available in their App Store. So Webroot cannot scan your iPhone sorry to say.
Webroot does offer two apps you can download from the App Store to backup your files and protect your internet browsing, called SecureWeb and Backup & Sync. You can find either of them by searching for "Webroot" in the App Store on your Apple iOS device. For more information on both of these products please use the information below.
Webroot Backup & Sync (for SecureAnywhere Complete subscriptions only)
Also here is the Webroot Mobile IOS User Guide using SecureWeb: