I just read on iPhoneAlley that loopt actually spams your contacts via sms. Has anyone had any problems with this yet? I have loopt and love it so far but wasn't aware it was doing this. So, I just deleted it. I hope the developers of this app remove this asap.
http://www.iphonealley.com/news/loopt-app-spams-your-contacts-sms
http://www.iphonealley.com/news/loopt-app-spams-your-contacts-sms