I've used one once also and the results where quite good to be honest, but you really need to do it in a decent heat, on a good summers day.
I used Rain.X kit
1
2
3
Follow the instructions to the T to get best results, really clean the area being treated.
4
5
I stuck a piece of cardboard inside the screen so i could see the chip correctly, then cleaned the area with both these products.
6
7
Made sure it was dry and dust free, some a calm day not a wind one if doing in a garage you should be ok.
You can see these little chips scratches etc.
8
Press on the spider tool has i called it, directly over the chip.
9
Making sure it screws down to the screen.
10
then you inject the filler and leave to dry,
11
Remove and use the paper after if need be, i think is correct if my memory is right.
12
It is never going to be as good when a professional chips job done, but is ok.