Download xls file in app browser

I`m trying to load a excel file from a webservice using NgCordova In App Browser. The webservice returns a Stream and I set the return content type to "application/vnd.ms-excel" It seems to work when I use Chrome and Ripple but nothing happens when running from iOS or Android.

What am I doing wrong?

How can I make it work?

This is the piece of code to make the call to webservice:

var string = 'http://10.1.25.56/Triacao.WAP/SVCTriacaoMobile.svc/DownloadPlanilhaTreino?param1=test.xls';

                            $cordovaInAppBrowser
                                .open(string, '_blank')
                                .then(function (event) {
                                    // success
                                }, function (event) {
                                    // error
                                });