var gameWidth:Int = 1920;var gameHeight:Int = 1080;
...
addChild(new FlxGame(	gameWidth, 	gameHeight, 	initialState, 	zoom, 	framerate, 	framerate, 	skipSplash, 	startFullscreen));
Lib.current.stage.align = StageAlign.TOP_LEFT;		Lib.current.stage.displayState = StageDisplayState.FULL_SCREEN;		var fill:RatioScaleMode = new RatioScaleMode();
FlxG.scaleMode = fill;
FlxG.camera.bgColor = 0xff000000;RatioScaleMode, this keeps the 1920x1080 aspect ratio for every device, creating black fringes.
Use instead FillScaleMode, it fits the whole screen, no black fringes. You just need to UPDATE this line:
var fill:FillScaleMode = new FillScaleMode();
Also import:import flixel.system.scaleModes.FillScaleMode;
if (zoom == -1) {	var ratioX:Float = stageWidth / gameWidth;	var ratioY:Float = stageHeight / gameHeight;	zoom = Math.min(ratioX, ratioY);	gameWidth = Math.ceil(stageWidth / zoom);	gameHeight = Math.ceil(stageHeight / zoom);}
addChild(new FlxGame(	gameWidth, 	gameHeight, 	initialState,	1,