I have an iPhone 5s running iOS 9.0.2. For the last couple of days the phone has been going unresponsive--the only thing that works is double clicking the home button and sometimes the ability to terminate apps that show up as a result of that double-clicking. My phone also feels very slow to use. Is the unresponsiveness due to a bug or failing hardware? Is there any information on how to optimize iOS 9 on the 5s, say by turning off certain features that consume CPU and are running by default? Another issue I've been having is that when I use Siri to look something up, if I'm lucky to get it to recognize what I'm asking, I still get an error of the type "Siri is unable to determine your current location" and it aborts. Didn't experience any of this with iOS 8.