Where has my internet network icon gone?

Until yesterday, on my HTC Wildfire, I had an icon on my home screen which toggled on/off my mobile internet connection. I used it a lot because when I am at home using WIFI I don't want to be paying the daily connection fee from Giff Gaff. If I am away from home it was a simple matter to click the icon to connect. It looked like a thermometer and changed colour when on. It has disappeared and I can't find out how I originally got it there.
Can anyone point me in the right direction?
Sorry if this has been asked before but I couldn't find a thread relating to it.

This is silly: I was in an area today that has no signal. Being near to France I usually pick up a French network. Several times I have noticed that upon returning home I still have no coverage and the only way to regain coverage is to switch off completely and back on again. Upon doing this I now find my missing icon has reappeared. Strange.

Thanks for your reply.
I tried that several times and could not locate the widget or app. It is a mystery where it went to and why it reappeared with a restart. I still don't remember where I got it in the first place. It is a very handy icon to have.