Find a list of all apps that launch at boot time
On Android 7+, you can do:

~$ pm query-receivers --components -a android.intent.action.BOOT_COMPLETED


Or:

~$ dumpsys package resolvers receiver | awk '/android.intent.action.BOOT_COMPLETED/{p=1;next}/:/{p=0}p {print $2}'


Related: Disable autostart on boot