The Federal Trade Commission is advising mobile app developers that it has its eye on technology that could allow phones to monitor TV viewing habits and relay that to targeted third-party advertisers. In a blog post Thursday, the FTC pointed out it was sending letters from the associated director of the Privacy and Identity Protection division–to app developers whose apps use software created by Silverpush that runs in the background and enables phones to “listen” for embedded audio signals in TV programs to determine what TV shows or ads are playing, even when the app is not being actively used. The app “could” create a log of such TV content…