We also have a free iPhone app at http://itunes.apple.com/us/app/truxmap-lite-food-truck-map/id391286574?mt=8

and free Android app (not that great) at https://market.android.com/details?id=com.truxmap

This has been a work in progress for over a year and a half, but I'm now feeling confident enough in the app to ask the HN community for feedback.