Mobile Viewing for Google Apps Script with Bootstrap - mobile

Question

I am trying to design a mobile first web app using Google Apps Script.
I would try to replicate the most basic Bootstrap page (http://getbootstrap.com/examples/navbar) in a Google Apps Script.
This is the way the bootstrap page should render on my mobile device:
but instead my page loads like this (ie. http://goo.gl/yZpgUg):
This is my code.gs:
function doGet() {
return HtmlService
.createTemplateFromFile('index')
.evaluate()
.setSandboxMode(HtmlService.SandboxMode.NATIVE);
}
My index.html is copied and pasted from http://getbootstrap.com/examples/navbar with CDNs replaced as appropriate.
I figured HtmlService.SandboxMode.NATIVE was important to get this to work but doesn't seem to work.
Dear world - any help would be greatly appreciated.
Cheers.
UPDATE 1 - (THANKS FOR YOUR RESPONSES!)
in IFRAME:
IFRAME console errors (2):
NATIVE console errors (lots):
Bottom line - clearly GAS is not liking it and doesn't seem super straight forward - I've ended up turning the GAS into an API which returns JSONP from the spreadsheet I need - much more straight forward. Thank you for all your help!

Answer 1

I know you decided to go another route, but I got this to work in the same scenario. You can simply add the meta tag on the GAS code using the following code:
var output = HtmlService.createHtmlOutput('Hello, world!');
output.addMetaTag('viewport', 'width=device-width, initial-scale=1');
So when you serve up your html in doGet add the meta tag. Check out this link for more information: https://developers.google.com/apps-script/reference/html/html-output#addMetaTag(String,String)

Answer 2

Apparently Google can't load Bootstrap from their server, try copying everything to GAS and include in the page as explained in best practices. Also switch back to IFRAME when testing.