Will we see the death of Twitter clients like TweetDeck or Echofon soon? Twitter on Friday issued a clear statement to developers that placed a moratorium on third-party apps.

Apps like Foursquare or Instagram are free to integrate Twitter into their services. Twitter is also fine with companies like Klout creating analytics tools. But Twitter's director of platform Ryan Sarver made the company's stance on apps that show and send tweets clear in a note sent to developers.