This app works only with the Xposed framework

It creates fake NetworkInfo and WifiManager objects that make other apps think they are using a WiFi even when your device is connected by other means to the internet.

When would you need that? I use it for HBO GO in my Android media box that has ethernet connectivity but the app ignores it. You might want to use it with other VOD or music streaming services that won't choose the highest quality over metered connections.
If you don't have a clear idea what are you going to gain by installing this app, you are better off not installing.

Be careful when you use it, especially if you don't have an unlimited data plan!

You might need to 'force close' some apps to pick up new settings or even restart your device.

If you are using Tasker or Locale you can use them to enable/disable Fake Wifi programmatically.

This app builds upon code from lemonsqueeze licenced under GNU GPL v3.
Source code is at https://github.com/chylek/FakeWifi