My app has a simple UI interface having simple buttons, date picker, picker view, table view, action sheet, toolbar, alert boxes etc. No images, no network access. Just plain simple UI. It accesses SQLite database a lot. ARC option is enabled. I have many questions to ask:

1. In .h files, I am defining IBOutlets like

   @property(nonatomic, retain) IBOutlet UIButton *bt;  
   

   Where do i need to do bt=nil? in didReceiveMemoryWarning or viewDidLoad

2. Live Bytes in Instruments tool is 4-5MB. Is it enough or I need to reduce memory usage? If so, how can I do so? Please mention few important points.

3. Also, what all need to be added to the following methods?

    applicationDidReceiveMemoryWarning
    UIApplicationDidReceiveMemoryWarningNotification