Autostart iphone apps
There are plist files in /Library/LaunchDaemons/ and /System/Library/LaunchDaemons/ which you can create which should work. Autostart / launchd. There’s also a launchctl command launchctl load /System/Library/LaunchDaemons/com.imalc.insomnia.plist this is a clue how to get an app to boot at startup