iOS log output from device or simulator

On macOS: Use the Console tool. Alternatively: idevicesyslog from libimobiledevice.

Install:

brew install libimobiledevice

Usage:

idevicesyslog --process Client

Client stands in for the process name (Client is the name of Firefox iOS).

via https://bsddaemonorg.wordpress.com/2021/04/12/analysing-ios-apps-log-output/