React-native componentWillUnmount not being called
<p>I'm running on Android and if I used the hardware back button to exit the application the componentWillUnmount function gets called.  However, if I use the square button to show the list of running apps and swipe to close the function does not get called.</p>

<p>Any ideas on how to detect when the app is being closed so that I can clear timers, save data etc.</p>

<p>Thanks.</p>