Yes, the horrible job of cleaning windows.
Windolene is my chosen method. Put it on, the rub it off, very difficult if your wrist are hurting.
Went to my daughters last weekend and they saved a dirty window to demonstrate their new gadget. Very impressed I was and I want one. Very light to use. I have read a few reviews, all of them good, even can use if for getting condensation off windows in the morning. Only bad thing that I read was that the battery didn't last very long.
http://www.amazon.co.uk/...;ref=pd_sl_9gwd4yp34v_b
Amazon was the first one that came up when I googled it, so you may get one cheaper somewhere else.
Paula x