One of the most frustrating experiences for any iOS user is a device stuck in a boot loop or on the Apple logo. Iremove Tools 1.3 includes an button, but more importantly, it features a "Deep Repair" module. This module re-flags corrupted NAND partitions and force-reinstalls the iOS firmware without erasing user data (where possible). It has shown particular success with error 4013 (often related to a hardware-check failure during restore).
Version 1.3 is available now. Licensing for professional EFI removal starts at Iremove Tools 1.3