Instagram has lost on useful feature on their mobile apps. Instagram users can no longer connect with their Twitter friends automatically.
This feature was powered by APIs provided by Twitter and they have disabled them for the apps offered by Instagram.
This looks like the latest step taken by Twitter to control their own ecosystem. Twitter already offers photo sharing capability on their own platform for instance.
Instagram users however still can post their latest shots on Twitter.
LinkedIn was recently the victim of a similar block. Twitter users can no longer sync their updates on their LinkedIn profile using the functionality offered there. This is however still possible using third party tools like IFTTT.