I have the tool also. You can get them at walmart or anywhere. If you get one, make sure it has multiple tips to accomodate different sized crystals. You can only use it if the back (flat side) has the glue already on it when you buy them. The tool heats the glue.
I used them on my capri's 3 years ago and wash them every week; they are still on!
Oh, you can also use an iron with those pre glued crystals.