[pinkfish]

I have an app which only works on 3G. The problem is that the majority of the time I actually need to use it is when I'm at home connected to WiFi.

I know there are apps which can force 3G use on a WiFi only app but is there anything which does the reverse?

ETA: My phone is rooted and I have Xposed installed so no problems with anything requiring that.

You can use Tasker. Create an action that will force 3G to be turned off and Wifi to be turned on (this is a separate plugin) when you run your app.

Unfortunately, Tasker is a paid app (but I think there's lot of Tasker releases here in mobilism *wink*). You can check this post for apps that can help you determine which of your apps will run on 3G or Wifi.

[xabdullahx]

Try this:
http://forum.xda-developers.com/xposed/modules/app-fake-wifi-connection-t2800416