Twitter and Amazon’s Kindle are the latest big names to get behind Microsoft’s new Windows Phone 7 (WP7) platform. Both companies plan to launch apps for the new OS; Twitter has already launched its WP7 app, a move which follows similar rollouts on the BlackBerry and iOS platforms, while the new Kindle app for WP7 will be available later this year. Amazon already offers Kindle apps for the iPhone, iPad, Android smartphones and BlackBerry smartphones.