Where a link may open on lightning app as its a one page app?

You would do this using the e.force:navigateToComponent method. Try this

In your markup

<ui:button label="ATTENDANCE" press="{!c.navigateToRollCall}"/>

In your controller, do something like

navigateToRollCall : function(component, event, helper) {

var evt = $A.get("e.force:navigateToComponent");

evt.setParams({

componentDef: "c:AttendanceRollCall",

componentAttributes: {

programId: component.get("v.program.Id")

}

});

evt.fire();

}

Thankyou