Detect VPN status
When a VPN is configured on a Windows Phone 8.1 device, non obvious badness will occur.
Even if it is not currently active it will intercept local network traffic and prevent some apps which are supposed to operate against a home network from working (UPnP, network shares, home media sharing, etc).
There is no way with the current SDK for a developer to detect this.
This leaves developers with only unappealing options:
1. Suffer with negative ratings because of broken functionality with apps that worked under 8.0 or without a VPN.
2. Prompt all users with a warning that they should make sure that the VPN is disabled before proceeding... including most users who have not enabled a VPN in the first place... and popping such a message almost every time the app is launched.
3. Re-write large portions of code as native code and use the Winsock APIs instead of the WinRT.
The correct answer, is Microsoft to provide a supported mechanism so that a developer can detect if a VPN is enabled, and only then pop a message asking that it be turned off.