How to see who they are texting?

On an iPhone there is no way to see who someone is texting, full stop: the Messages database is sandboxed and no app, backup viewer or profile can reach it without the Apple ID. On Android, a monitoring app on the device shows the threads; nothing does it remotely.

iPhone options, honestly:

• Screen Time → Communication Limits — you choose who can be contacted during downtime and for how long. It controls the list, it does not report activity.
• Family Sharing with a child Apple ID — purchases, location, screen time; not messages.
• One shared Apple ID for Messages — with younger children this is common, and messages appear on every signed-in device. That is Apple's sync, not surveillance, and it stops working the day they get their own Apple ID.

Android options: a monitoring app with SMS permission on a device you administer, giving threads with contact names and timestamps. Same rule as everywhere: the device must be yours to manage, and the person should know.

What is not real: entering a number on a website, "SMS tracker" apps, or anything that promises iPhone message access without the Apple ID. Those pages exist to collect card details.

Where our app fits. Ultimate Phone Spy runs on Android 4.0+, Windows and macOS (supported devices) — no iOS product. For an Android child device it shows SMS/MMS and call logs; for an iPhone, Screen Time is the whole honest answer.