Deca5 (pronounced “Decaf”) is a GUI tool to downgrade and jailbreak A5 devices. It was built with three things in mind: user-experience, performance, and reliability. Deca5 is unique, it is built entierly using Swift, SwiftUI, and C — it is built for modern versions of Mac OS. Moreover, much attention was given to the tool’s design, look, and feel. And of course, Deca5 fully open source — anyone can feel free to modify the tool to their liking.
Building Deca5 was the fruition of what can only be described as a multi-year quest. For years, I’ve been interested in reverse engineering, mainly to better understand how devices function. This merged with my love of legacy iOS devices to produce Deca5. The contraction of the tool was an intriguing adventure for me — to say the least. It required combining my iOS app dev skills in Swift and SwiftUI with my knowledge of C, ARM ASM, and OBJ-C.