Look up UIDocumentInteractionController. It's been around a while.<p>You can also do quite a lot with URL Schemes but more apps need to implement support and publish their requirements.<p>There is also the X-URL-Callback spec which could be implemented by more apps. Google is using this spec on iOS.<p><a href="http://x-callback-url.com/specifications/" rel="nofollow">http://x-callback-url.com/specifications/</a><p><a href="https://developers.google.com/chrome/mobile/docs/ios-links" rel="nofollow">https://developers.google.com/chrome/mobile/docs/ios-links</a><p><a href="https://developer.apple.com/library/ios/documentation/uikit/reference/UIDocumentInteractionController_class/Reference/Reference.html" rel="nofollow">https://developer.apple.com/library/ios/documentation/uikit/...</a><p>Finally, let's get away for guessing about what Apple might be doing. It was easy enough to search "iOS open in" to find this support to support this feature and it had been around a few years. There's no reason to suggest that Apple is copying Android on this feature.
This is one of the reasons that I find Android far more useful for most workflows than iOS. I was amazed that Twitter and Facebook integration had to be built in manually.
Apple seems to be experimenting with native inter-app sharing on iOS 7 within the iMessage app. If you try to share an image you’ve received through iMessage you’ll notice a much larger selection of sharing options than normally available on other iOS apps.