You will need to jailbreak your device in the first place in order to install OwnSpy on your iPhone. You can follow this great tutorials to find how to do it.
WARNING: OwnSpy only supports devices with iOS 9 or below!!
When your iPhone is jailbroken you will find a new app called Cydia, open it, search for OwnSpy and install it.
Once installed you will be able to register your device and choose your username and password to acces your web userpanel.
After completing your registration your device will start uploading data to the cloud so you can monitor it from your userpanel.
