Just turning on the built-in https uses a 'self-signed' certificate, which browsers consider to be inherently risky. In some cases you can make an exception and accept it anyways, in others you can't. It causes problems with html5-based apps (like SubFire) that are packaged for Android or IOS, in that you can't make an exception for self-signed and the platform will refuse to connect.
The proper solution is to have your own domain and purchase a certificate signed by a trusted certificate authority.
