Instagram may not have a native app available on the iPad, but Iris App is here to fill that void. You may not be able to upload photos to the popular photo sharing service, but Iris App does allow you to browse your feed, featured photos, "like" and comment photos, and more.
Along the left hand side, you'll see a thin column that give access to your main feed, featured photos, your profile, search, and the photos you've liked.
Your home feed is displayed as a grid of polaroids. Each Polaroid shows who's photo it is and the number of likes and comments. These images are nice and big and the design is very clean looking. If you want to "like" the photo, just double tap! You can also tap the heart and a sidebar on the right will slide out that lists all the users who have liked the photo, links to their profiles, and the option to "like" the photo. Tapping the speech bubble is very similar, except for comments. If available, you can also view the photo's location on a map.
Tapping on a photo will slide a larger version of the polaroid up from the bottom of the screen that looks exactly the same with the addition of an excerpt of the caption. Which leads me to my biggest disappointment -- if the caption is more than about 40 characters, the only way to view the caption is in the comment view. I think captions should be viewable from the polaroid/thumbnail view. I like to see caption as I casually scroll and browse through my feed.
If you tap on a user's avatar, you'll be taken to their profile. Along the top, you see their name, bio, number of followers and following, a button to follow/unfollow, a "thumbs-up" to recommend the user via email, and a button that lets you view all the user's photos on a map.
The photos in profile mode are displayed much smaller than on your main feed -- there is 4 photos per row vs. two photos per row. But there's a trigger on the bottom of the sidebar that lets you switch to the larger, more detailed thumbnails if you prefer.
The featured photos and liked photos pages also feature these smaller thumbnails, but oddly, there is no option to view them larger.
I often use Instagram to browse through photos even when I'm not sharing my own photos and have always longed for an iPad version. Given the fact that Facebook now owns Instagram and that the Facebook iPad app took ages to release, I'm not expecting an official Instagram iPad app anytime soon. I'm just glad to have Iris App as a fantastic alternative.