Has anyone successfully install an IOS app that is uploaded to a private AppExchange from Salesforce1 app? The "install" button never works, like the demo from DreamForce 2014(https://developer.salesforce.com/blogs/developer-relations/2014/12/implementing-single-sign-on-mobile-applications-salesforce-identity.html). I thought it was an accident but I'm having the same problem. I only can install an app from a fullSite Version but never from a Salesforce1 or Salesforce1 web app.
This is correct - when you are inside a WebView, you can't access the local OS resources such as storage, file system and for app installation, these are required. I have distributed a few apps via private App Exchange and people are able to install it via browsers without any issues.