If your phone doesn't want to boot up again after the update, it gets stuck in a black screen, follow this tutorial where we root the Galaxy SII with Odin and put an official Samsung Android 4 ICS on it.
If you dont't want that every time you take a picture with your Android device, it gets instantly uploaded to your Google+ profile, this tutorial's for you.
One of the more important features of any mobile phone, let me show you how to set an alarm so it will only ring on the specific days and not on weekends when you need your sleep the most.