If you haven't picked up the Lovecraftian Advent calendar app for iOS and Android devices, don't worry, you still have time and now there's a free option. Free is good, right?
Red Wasp Design just released a free, light, version of their Cthulhu Christmas Calendar. Both the free and light versions let you see the collection of Cthulhu Christmas art and quizzes drawn from the Dec. 1 through Dec. 9 entries. To see more you have to pay for the full app. Sure it's sort of useless to you now, but at least you can see if you want to drop a buck to see a Shoggoth dropping a letter to Santa in the mailbox.
Cthulhu Christmas Calendar [Red Wasp Design]