I've been working on a new and improved version of TinyUmbrella that will, among other things, allow you to restore your iDevice without iTunes. With the holiday season and work, this will take me a bit to get working the way I want it. I appreciate your patience and your support. You guys are awesome :) No ETAs yet but I'll post updates here and on twitter.
UPDATE: By popular demand I've updated 4.21 to support Apple TV 4.2.1 SHSH's. I'm still working on the new iteration of the Tiny family. Stay tuned!