Here’s my take on this.
You essentially have two main pathways, each with its own trade-offs.
The first is using Apple’s native ‘Find My’ service, which works through Family Sharing or direct location sharing between friends. The upside is that it’s a built-in, reliable iOS feature. The downside is that it requires the other person to have actively shared their location with you first. It’s straightforward but depends on that initial setup.
The second pathway involves third-party monitoring services. These often work by using the person’s Apple ID and password to access iCloud backups and location data. The advantage here is that you can sometimes get more detailed location history. However, this method is dependent on having the correct credentials and ensuring two-factor authentication can be managed. It’s a different approach for a different set of circumstances.