Google now is sort of an intelligent personal assistant that depending on the data that Google gathers knows you pretty well. One of the coolest functions of Google now is the voice recognition functionality.
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.
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.
If for some reason your Android powered smartphone does not perform as good as it used to, or you want to sell it I suggest you to bring it to its original factory state.