First you should create a file and name it as xx.script: (or other proper name)
tell application "iOS Simulator"
tell application "System Events"
tell process "iOS Simulator"
tell menu bar 1
tell menu bar item "iOs Simulator"
tell menu "iOs Simulator"
click menu item "Reset Content and Settings…"
tell window 1
click button "Reset"
You can put in any place you want. What I did was just in my user folder.
Then you can verify the script by run this in you Terminal. (make sure your simulator is running)
then you can put it into your xcode like this:
It will reset your simulator before you run your app everytime.