Instagram on the iPhone just got an update ever since Facebook acquired them. Version 2.5 of the app adds a whole new tab - "Explore". It replaces the "Popular" section that showed photos with the most likes. You can still see the top ranking photos under "Explore" but Instagram is also letting you search by username or hashtag now.
With Facebook's Open Graph, this means you have the option to post all the photo Likes you've made on Instagram to your Facebook account. Brand page managers can post directly to their Facebook page without leaving the app.
Another feature in 2.5, is getting to your Camera Roll. Instead of the two click operation required to post the photos you've already taken, now its just a tap and hold the camera button and you'll go straight there. The app also seems faster a little.
Will the Android app get the update as well? We'll let you know when we find out!