In case you are running Lumia Cyan on your devices you can now control whether to use or not use cellular data when your WiFi connectivity gets limited for some reason. It can be due to even moving from one room to another in your house.
You can go to Settings—->Mobile+Sim, and select “don’t use mobile data” or “use mobile data” for doing so. This certainly helps in saving Cellular data. Even if the WiFi signal has become weak your device will keep using it.
we have everything about Lumia Cyan and Windows Phone 8.1 which includes:- Full Changelog, Hands-on demo videos and all above Tips & Tutorial articles on our dedicated Lumia Cyan and Windows Phone 8.1 page.