Anyone use TomTom for Iphone for Hiking GPS

http://www.tomtom.com/products/product.php?ID=940&Category=2&Lid=4

Is currently 1/2 price off for the Iphone, $50 v. $100, during the Christmas shopping season.

I use a GPS on the JMT only for stopping purposes, as hiking groups I organize hike at different speeds, with the fastest hiker being about 2-3 hours ahead of the slower hiker each day. We have just one GPS programmed with stop points in it so the lead hiker knows where the stopping point is. Yes, most of the time, the Tom Harrison Map is fine, but not all the times – several days, having the GPS is very nice.

I've been using The Garmin Foretrek 101 which is only 2.5 oz and does the trick just fine. But I've wondered about using the Iphone instead of bringing along the Garmin Foretrek. Right now I ship the Iphone to Lone Pine c/o General Delivery awaiting me at end of hike. Which is a pain.

Anyone know of a GPS app for the Iphone that lets you route a hike with stopping points, like one can do with any Garmin GPS? Is the Tom Tom app worth it? I know it would be nice for driving assistance but that is not critical. The built in Google Maps feature for the Iphone works great too. Comments from users?