Intents has done a great job on android - I have some minor quibbles with it, but it's light years ahead of what iOS had pre-Ink

Edit since I can't reply to milesokeefe: As an avid android user (Galaxy Nexus), some things about intents that I feel are poorly designed: - No support for bidirectionality. There's no sense of "I'm done with this action, take the results and send it back" - No sense of intelligence in terms of what actions are shown. As far as I can tell, it seems to be filtered by content type, sorted by Most Recently Used. - Unclear actions - iOS suffers the same issue, where it's not really clear what it means to open in another application.