RestoreTools.pkg is an internal software package developed by Apple for its employees, engineers, and factory workers at facilities like Foxconn. It is primarily used for advanced diagnostics, debugging, and flashing firmware onto iOS devices, often providing much deeper customization than consumer tools like iTunes. The Apple Wiki Included Applications and Utilities
Pro tip: Use the --dry-run flag first to see exactly what will change. restoretoolspkg best
To truly make RestoreToolsPkg the best solution for your workflow, follow these best practices: RestoreTools