Hi! I see that the Gabb Messenger app is missing from your child's iPhone. Let’s work together to get it back on their phone.

First, just to clarify:
- Has the app been installed before and now it's disappeared?
- Or is this the first time you're trying to set it up on your child’s phone?
- Also, is your child's phone a Gabb phone or a regular iPhone?

Knowing a bit more will help me guide you better.

In the meantime, here are some straightforward steps you can try on the iPhone with iOS 18.6.2:

1. Search for the App
Swipe down on the home screen and use the search bar to type "Gabb Messenger." Sometimes the app might be on a different page or in a folder.

2. Check if the App is Hidden or Restricted
Go to Settings > Screen Time > Content & Privacy Restrictions. Make sure that app restrictions are not hiding or blocking Gabb Messenger.

3. Reinstall the App
If you don't find the app, open the App Store, search for "Gabb Messenger," and download or reinstall it. The Gabb Messenger app is available for iPhones on the App Store.

4. Verify Gabb ID Login
Ensure your child is logged into their Gabb ID on their device. The Gabb Messenger app requires this for proper operation.

5. Check Parental Controls and Permissions
Since Gabb phones and apps often have parental controls, make sure video calling or messaging features are enabled for your child in your parent Gabb Messenger app or MyGabb account.

If after these steps the app is still missing or not showing up, let me know what you find and we can dig deeper, including checking if any account or device-specific settings might be at play.

Would you like me to guide you through any of these steps?