You welcome Johnson, I'm glad that I answered your question....
Well, what I could about that application on the store of Tom Tom, that yes! It's compatible with the itouch but you a car kit(which is available for sale on the apple store) which has a built-in gps receiver giving you a fully functional gps system on your iPod. I think the price is like a 100$ dollars on the apple store ofctge ton Tom car kit.....
But there is a better product which is coming soon to stores which gives you same ability of gps on your iPod.....
Keep your eye on this one:
http://www.gpscradle.dualav.com/nav.html
I don't know when it's going to be released, but appears to be a GPS solution so many iPod touch users have been waiting for.