One example (of many, many examples) that shows the difference in API design between Apple and Google. This example shows the code required to load a list of turn based matches.

Loading turn-based matches comparison

// Apple API for loading all your turn-based matches

[GKTurnBasedMatch loadMatchesWithCompletionHandler:^( NSArray *matches, NSError *error )
{
    // there is either an error or a result. nice and simple.
	if( error )
		log( "print a useful error: " + error );
	else
		log( "the matches are here: " + matches );
}];





// Google API for loading all your turn-based matches on Android

int[] statuses = new int[] { TurnBasedMatch.MATCH_TURN_STATUS_MY_TURN, TurnBasedMatch.MATCH_TURN_STATUS_THEIR_TURN, TurnBasedMatch.MATCH_TURN_STATUS_COMPLETE };
Games.TurnBasedMultiplayer.loadMatchesByStatus( helper.getApiClient(), statuses )
	.setResultCallback( new ResultCallback<LoadMatchesResult>()
	{
		@Override
		public void onResult( LoadMatchesResult result )
		{
			if( result.getStatus().getStatusCode() != GamesStatusCodes.STATUS_OK )
			{
				log( "we don't have a useful error but we have an integar that we have to look up in the documentation: " + result.getStatus().getStatusCode() );
			}
			else
			{
			    // so, we just wanted a List of matches but Google would never make it that simple. We'll create the
			    // matches List and fill it ourselves
				List<TurnBasedMatch> matches = new ArrayList<TurnBasedMatch>();
				
				// what do we get from Google instead? a LoadMatchesResponse (result.getMatches returns it) of course!
				// and what is inside a LoadMatchesResponse? three TurnBasedMatchBuffer objects! to get those matches we
				// asked for we have to loop through each of the three TurnBasedMatchBuffers and extract the matches
				// one-by-one.
				for( int i = 0; i < result.getMatches().getCompletedMatches().getCount(); i++ )
					matches.add( result.getMatches().getCompletedMatches().get( i ) );
					
				for( int i = 0; i < result.getMatches().getMyTurnMatches().getCount(); i++ )
					matches.add( result.getMatches().getMyTurnMatches().get( i ) );
					
				for( int i = 0; i < result.getMatches().getTheirTurnMatches().getCount(); i++ )
					matches.add( result.getMatches().getTheirTurnMatches().get( i ) );

				log( "yay! we finally got what we asked for! matches: " + matches );
			}
		}
	});
	
	


// oddly enough, the iOS Google API is more to the point though still you have to search deep in the documentation to
// figure out that to load turn-based matches you use the applicationModel and call reloadDataForKey with the magic
// string GPGModelAllMatchesKey. why not just expose a loadMatches method on a relevant class such as GPGTurnBasedMatch?

[[GPGManager sharedInstance].applicationModel reloadDataForKey:GPGModelAllMatchesKey
											 completionHandler:^( NSError *error )
{
    // there is either an error or we can fetch the results
	if( error )
		log( "print a useful error: " + error );
	else
		log( "the matches are here: " + [GPGManager sharedInstance].applicationModel.turnBased.allMatches );
}];