I thought this was an FCC mandate (to track GPS information for cellphones) after 9/11. The real issue is that this is not encrypted in anyway so anybody can get the information if they have access to the file.
As I recall the mandate was that all phones must have GPS in them and it has to be available real time under particular circumstances.
As for this file it isn't really available to anyone at any time. They have to have your iphone or your computer. And even then it isn't like they tap 4 times and suddenly the list is there. They have to have access to your file system via specifically written programs etc. Most of the time anyone that has your iphone wants a free iphone so they first thing they do is to wipe it to erase any 'find my' type stuff. IF they are goofing around they are in your even more open and accessible email, facebook etc. Although if you put on a passcode lock with the auto wipe they might not even get that far.
I would be more worried about the tool on this pair's website. It calls out to at least two sites. One is google maps but what is the other one. I mean we only have their word that they aren't recording any data about us when we use their software.