Pwn20wnd throw out the unc0ver v3.7.0~b1 update with full-fledged A12/A12X support with Cydia and system-wide tweak injection. In other words, a couple of months ago, Pwn20wnd released iOS 12.1.3 - iOS 12.2 & iOS 12.
https://thetechpapa.com/uncover-jailbreak-added-a12-a12x-support/