Only five days after launching on Android, Vine has surpassed Instagram in its total daily shares on Twitter, according to metrics by Topsy. While Instagram's numbers have been fairly flat over the past month, Vine has continued to grow — and there's a good chance that opening the app up to another large segment of the market had an impact on that. On Friday, links to vine.co were shared over 2.5 million times, with instagram.com links hovering just below 2.2 million.

However, Instagram still remains one notch ahead of Vine on Google's list of top free Android apps. And without hearing from both apps' developers, we can't know exactly how many active users and daily creations there are within the apps' own networks. For Instagram, the flat numbers probably aren't helped by its refusal to integrate with Twitter cards. Following the launch of Instagram web profiles, the company cut off the easy expansion of shared photos within Twitter streams, making it just a little less convenient to use. As for Vine, being owned by Twitter certainly can't hurt.