Flickstagram

 Flickstagram  was a service that allowed you to silo-hop from Instagram to Flickr. It was created in 2012 after Instagram was acquired by Facebook and changed their terms of service. Flickstagram migrated 2,747,740 photos to Flickr before it was shut down in 2016, after another ToS update made it impossible to create an application like Flickstagram that would comply with their ToS.