I received a text saying .....Your friend has invited you to check out Receipt Hog. Earn cash and rewards for simply scanning your receipts: http://app.receipthog.com/install/uut0s8rd
When I texted back and said who is this?  I got a message saying to configure my sms url to change this message. Is this some kind of app to code messages so others can't read it without the app or whatever? STRANGE!

pre-recorded message, I won some kind of vacation

Got a text message a few weeks ago saying I was signed up for shop-aroo service.  Now I keep getting calls telling me I won a free vacation.   There doesn't seem to be anyway to opt out of it.