$app->helper(
    is_mobile => sub {
      my $self = shift;
      $self->app->log->debug( $self );
      $self->app->log->debug( $self->tx );
      $self->app->log->debug( $self->tx->req );
      return $self->tx->req->headers->user_agent
        =~ /(iPhone|iPod|iPad|Android|BlackBerry|Mobile|Palm)/ ? 1 : 0;
    }
  );