AngularJS ng-if for $rootScope

Question

In an Angularjs Project I'm trying to get an <a/> to pnly show if $scope.page == 'app'

in my controller $rootScope.page = 'app' and so is $scope.page = 'app' but when I use the following in my DOM it doesn't show when I'm on that page.

<a ng-if="page == 'app'">Show Me</a>