I tested this on my Asus/Google Nexus 7 and it did not allow me to scale. My app is on html pages and packaged with PhoneGap. Everything works fine except for the scaling.

Code:
<meta name="viewport" content="width=device-width, initial-scale = 1.0, minimum-scale = 1.0, maximum-scale = 5.0, user-scalable = yes">