var gad = new ol.source.GeoJSON({
    'projection': map.getView().getProjection(),
    url: 'http://localhost:8080/geoserver/wfs?DATASTORE=Framework&service=wfs&version=2.0.0&request=GetFeature&typeName=opengeo:addr_to_geocode&outputFormat=application/JSON'
});

var gad3 = new ol.layer.Vector({
    title: "Name",
    source: gad,
    style: new ol.style.Style({
        image: new ol.style.Circle(({
            radius: 3,
    fill: new ol.style.Fill({color: 'yellow'})

        }))
    })
});
map.addLayer(gad3);

The layer http://localhost:8080/geoserver/wfs?DATASTORE=Framework&version=1.1.0&typeName=cite:tropics&outputFormat=application/JSON&SERVICE=WFS&VERSION=1.0.0&REQUEST=GetFeature&TYPENAME=sf:restricted&SRSNAME=EPSG:26713&username=admin&password=geoserver is not a valid layer and can not be added to the map.