How easy is it to integrate facebook in your game?

Some people have told me its very easy but I tried integrating it fully for 3 whole weeks, trying to solve all kinds of problems and in the end had to give up. The last problem I was totally stuck with is, when I run the game on device and press the facebook login button, the game crashes. Any idea how to debug this sort of problem. Device logs doesn’t show anything at that point.

The answer to this question on SO states that:

This is a bug, You can edit your android manifest in Plugins/Android and add android:configChanges so that FBUnityLoginActivity isn’t destroyed when orientation/whatever changes:

<activity 
    android:name="com.facebook.unity.FBUnityLoginActivity" 
    andrid:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen"
    android:theme="@android:style/Theme.Translucent.NoTitleBar.Fullscreen">
</activity>

you may also want to remove “Translucent” from activity style.