This feature creates the cache for mobile devices. This is a premium feature. It does not exist in the free version.
If you use a responsive theme, no need to use the mobile cache feature. You should disable “Mobile” and “Mobile Theme” options.
If you use a mobile theme, you should enable both “Mobile” and “Mobile Theme” options.
How it works
You need to select these two options to enable the mobile cache feature.
The feature creates a folder which is “wpfc-mobile-cache”.