Legacy iOS Kit

Legacy iOS Kit is an untethered (semi-tethered on iPad 2 4.3.x) jailbreaking tool which supports all 32-bit iOS devices running iPhone OS 3.1.3 to iOS 9.3.4, except iOS 9.0-9.0.2 (on all devices) and iOS 8.0-8.2 (on A5 and A5X devices). It requires an Arduino with USB Host Shield for A5 and A5X devices that aren't on iOS 5.0-6.1.2.

In addition, this tool provides several other useful functions, such as downgrading with iOS 5 HFS Heap Buffer Overflow and De Rebus Antiquis as well as to OTA signed versions, sideloading on Linux, dumping onboard blobs for 32-bit devices, and more.