This documentation: Documentation/Bundle/Resources/Information Property List/Data and storage/NSSupportsPurgeableLocalStorage says:
Property List Key
NSSupportsPurgeableLocalStorage
A Boolean value indicating whether the app continues working if the system purges the local storage.
Under what conditions does the system "[purge] the local storage", and does this mean the entire local storage for the app? I can see how when a user deletes an app the local storage would be deleted, but then the app would not continue working, since it's no longer on the device.