What is CheckRa1n Jailbreak? The CheckRa1n Jailbreak is an iOS jailbreak tool developed by the CheckRa1n Team using a powerful BootROM exploit called CheckM8 which cannot be patched by Apple on the already-vulnerable devices. This makes the CheckRa1n jailbreak a very stable and very powerful jailbreak tool with a pretty good safety record. CheckRa1n itself