This page of the Facebook iOS SDK explains how to have a single Facebook app ID shared across multiple iOS apps. However I am unable to find the same documentation in the Android area of the Facebook Developer site. Has anybody else had experience doing this or is it simply not available in Android?
Easier than iOS,
You can use one Facebook app ID in multiple Android apps.
check this link here
and I quote :
Share app ID across Apps
You can use one Facebook app ID in multiple Android apps. Just use the
same app ID in another app for login, sharing, and so on.
For deep linking and opening your app through notifications and other
means, we only support a single package name/class name combination.
If you want multi-app support for deep linking, see App Links.