Backup script for 3c toolbox system apps. Automatically re-add the 3c toolbox system app and helper apk to/system/priv-app when installing a new nightly. If you don't install 3c toolbox to system partition and this causes a problem, remove line 13.

99-3ctoolbox.sh

#!/sbin/sh
# 
# /system/addon.d/99-3ctoolbox.sh
# During a CM12.1 upgrade, this script backs up 3c toolbox apks
# installed in /system/priv-app, /system is formatted and
# reinstalled, then the files are restored.
#

. /tmp/backuptool.functions

list_files() {
cat <<EOF
system/priv-app/ccc71.at.apk
system/priv-app/ATSystem.apk
EOF
}

case "$1" in
  backup)
    list_files | while read FILE DUMMY; do
      backup_file $S/"$FILE"
    done
  ;;
  restore)
    list_files | while read FILE REPLACEMENT; do
      R=""
      [ -n "$REPLACEMENT" ] && R="$S/$REPLACEMENT"
      [ -f "$C/$S/$FILE" ] && restore_file $S/"$FILE" "$R"
    done
  ;;
  pre-backup)
    # Stub
  ;;
  post-backup)
    # Stub
  ;;
  pre-restore)
    # Stub
  ;;
  post-restore)
    # Stub
  ;;
esac