Since Cydia is broken on iOS 4.2.x, the new Redsn0w 0.9.6b3 released today supports iOS 4.2.1 so that developers can make their jailbreak-apps compatible before Apple releases the final firmware to public. Using this version of Redsn0w, you can now install jailbreak-apps without using Cydia.
Your jailbreak-app package however must be in a format that Redsn0w can read. i.e. gzip-compressed tar file, and it must be around 15MB in size. For our convenience, The iPhone Dev Team has released OpenSSH package in .tgz format which Redsn0w can identify. Follow the instructions below to install it on your jailbroken iOS 4.2.1 device.
Join The Community