"Both of them are worrying their third-party developers somewhat. Twitter wants to move on with making Twitter a business and so it needs to take some control over a platform that it claims is too fragmented. Ryan Sarver, Twitter's platform product developer says that with more people joining Twitter and accessing the service in multiple ways, "a consistent user experience is more crucial than ever". He's actually asked developers to stop making apps and tools that focus on the basic Twitter functions.
"Frankly, users don't seem to agree and are happy enough to pick and choose from the innovative apps and tools that third-party developers have been creating away while Twitter sat quiet. But on the plus side, Twitter isn't going to stop the use of hugely popular clients and is going to only insist that the companies that developed them follow a set of stringent rules on privacy and security. Great, but I wish they were handling it differently instead of seeming to forget that it isn't Twitter that thought up compelling ways of making the platform usable - it's the developers. For heaven's sake, you couldn't tell who was saying what to whom until clients like Tweetdeck came along."