How to spy on text messages without installing software?

To spy on text messages without installing software is possible if the target device runs on the iOS operating system. The thing is to have a cloud-based OS that backs up the data from the device. This allows spying on the target device without physical access to it. That way, it’s enough to know the iCloud credentials and make sure the iCloud backup is enabled on the target device. In the rest of cases, it’s impossible to spy on text messages without having once installed it on the target device, which requires a one-time physical access to it.