It was only a matter of time before someone decided to put two Instagram photos side-by-side and ask the age-old question: which one is more appealing? That's exactly the premise behind prurient new site Hotstagram.

Launched by a 27-year-old who goes by the pseudonym "Captain Kirk," the site splits Instagram pics of girls and guys into two different categories, then pits two random photos against each other and asks the viewer to pick "who is hottest."

Users and can rank dozens of photos in a matter of minutes with a seemless transition from one pair of photos to the next. Kirk even built in fail-safe feature that lets the user navigate back to the previous page and revote on a pair of photos -- you know, in case someone accidentally clicks on a not-so-hot photo.

Kirk debuted the site Monday. His introductory tweet:

For anyone who has seen "The Social Network," Hotstagram may be reminiscent of a similar hot-or-not ranking site featured in the film called Facemash. You know, the one that lead to the creation of Facebook, which recently purchased Instagram for a cool $1 billion.

Instagram users can submit their pics to the Hotstagram website by adding the #hotstagram hashtag to their Instagram photo uploads.

Hotstagram uses a bubble sort algorithm to rank the photos. All photos are then ranked according to up and down votes and the top batch of pics for girls and guys are featured on the respective leaderboard pages. For the most part the top ranks are filled with scantily clad girls -- it is swimsuit season -- or leading men from TV shows or movies.

The system is relatively simple. After all, it only took Kirk a weekend to code Hotstagram.

Aside from his age and preferred TV show, not much is known about Hotstagram's founder. Business Insider revealed he works for a start-up in San Francisco called Tracks.by, which promotes artists seeking to release tracks or music videos.

While Hotstagram is not endorsed or certified by Instagram or its publisher Burbn Inc., Kirk assured Business Insider that he's confident he is in compliance with Instagram's terms of use.

Kirk even added a feature that lets Instagram users to remove their photos from Hotstagram.

While you may be hurrying over to Hotstagram's site to try it out for yourself, don't be discouraged if you receive a 404 error. After its debut yesterday, Kirk said he saw 150 ratings a second". We can only assume that number has skyrocketed since then.

Also on HuffPost:

If Instagram isn't your thing, try out one of these nine other iPhone photo apps.
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  • Camera Awesome

    The free app from SmugMug is more of a wholesale camera app than a filter specialty app -- its specialty "Awesomize" button is a powerful auto-fix button with a great name -- but it does come with a healthy serving of 9 Instagram-like camera filters; these filters can be used with a cool sliding scale functionality of distortion so that you can choose the hipness level you hope to achieve with the filter. It's super popular in the app store, and it also reminds me of <a href="http://en.wikipedia.org/wiki/Mike_Awesome" target="_hplink">the late great WCW/ECW wrestler Mike Awesome</a>, who delivered one of the greatest Power Bombs professional wrestling has ever seen. Wait, what were we talking about? Oh, right: Filters. There are also 63 more filters available for download; you can pay $0.99 for 9 filters or $3.99 for all 63. <a href="http://itunes.apple.com/us/app/camera-awesome/id420744028?mt=8" target="_hplink">Camera Awesome is free in the iTunes App Store</a>.

  • Pixlr-o-Matic

    Pixlr-o-Matic is your standard phone camera, plus a whole lot (A WHOLE LOT) of really nice filters and aftereffects for your pictures. In addition to 25 Instagram-like filters that can be added after the picture is taken, Pixlr-o-Matic adds 30 free light effects that integrate with your photo, as well as a large selection of borders. If you upgrade to Pixlr-o-Matic PRO for $0.99, you can add dozens more filters and effects, and perhaps learn how to pronounce "Pixlr-o-matic" (my best guess: pix-lur-o-MAT-ic). BONUS: Pixlr-o-Matic also comes with a desktop app, which you can <a href="http://pixlr.com/o-matic/" target="_hplink">try out right here</a>. Go on, make funny faces at your webcam at work! Pixlr-o-matic is <a href="http://itunes.apple.com/us/app/pixlr-o-matic/id450263811?mt=8" target="_hplink">free in the iTunes App Store</a> and <a href="https://play.google.com/store/apps/details?id=pixlr.OMatic&hl=en" target="_hplink">in the Google Play Store</a>.

  • CamWow

    CamWow is a camera app that's all about effects; unlike Pixlr-o-Matic and Camera Awesome, CamWow adds the effects in real-time, so you can see what the filters will look like as you're taking the photo. Instant gratification, as Rupert Wainwright might have said. The free version of CamWow is essentially pointless: A banner ad stretches across the bottom of the app, and you have to pay $1.99 to remove a hideous, Word Art-looking CamWow watermark from your photo. CamWow is "free" in <a href="http://itunes.apple.com/us/app/camwow-free-photo-booth-effects/id418368641?mt=8" target="_hplink">the iTunes App Store</a> and with a $1.99 in-app purchase you can really try it out.

  • Hipster

    No, this app doesn't show you what you would look like if you wore skinny jeans and smoked like a French person; rather, Hipster is a photo-sharing platform that turns your pictures into rectangular postcards of a sort. You can add text and a location to your photos (that's where the "postcard" analogy comes in), as well as a selection of 10 filter "themes." Like Instagram, Hipster boasts an active community of photo-sharers. Full disclosure: AOL, Huffington Post's parent company, <a href="http://techcrunch.com/2012/03/15/aol-snaps-up-hyper-local-photosharing-app-hipster/" target="_hplink">recently acquired Hipster</a>. Hipster CEO Doug Ludlow <a href="http://techcrunch.com/2012/03/15/aol-snaps-up-hyper-local-photosharing-app-hipster/" target="_hplink">confirmed to TechCrunch</a>, however, that the app will live on. Too bad Hipster went totally corporate, though, man, it was so much better when no one had ever heard of it. I was actually the fourth person to ever download Hipster, and man was it just <em>a raw experience</em> back then. Hipster is free <a href="http://itunes.apple.com/us/app/hipster/id461983020?mt=8" target="_hplink">in the iTunes App Store</a> and requires a signup.

  • Picplz

    Picplz is another social photography app with a strong set of filters for you to augment your pictures with, as well as a huge photo editing suite powered by Aviary. It is also difficult to pronounce ("Pic-pullz"? Who taught these Silicon Valley types to spell, Professor Icanhascheezburger?) Anyway, since we're looking at filters: Popular ones include the "Russian Toy Camera" and "The 70s"; there is also an option to draw on and "meme" your photo, which you can see above. The real appeal of Picplz, however -- more so than the filters, and more so than the social component, might just be its robust in-app editing capabilities. If you don't know Aviary, it's a lightweight photo editing app for the web <a href="http://www.aviary.com/" target="_hplink">that you can check out here</a>; on a social photography app, it's killer. Picplz is available for <a href="http://itunes.apple.com/us/app/picplz/id382339383?mt=8" target="_hplink">free on the iTunes App Store</a> as well as <a href="https://play.google.com/store/apps/details?id=com.picplz.rangefinder&hl=en" target="_hplink">on the Google Play Store</a>.

  • Tadaa

    Speaking of excellent free iPhone cameras with a heavy focus on filters: Tadaa is a beautifully designed app with a ton of filters that can be viewed in real-time and adjusted after the fact, as well as options for rapid-fire shooting and tilt-shift photography (the thing you can use to <a href="http://en.wikipedia.org/wiki/File:Oregon_State_Beavers_Tilt-Shift_Miniature_Greg_Keene.jpg" target="_hplink">make it look like you're shooting miniatures</a>). It's one of the best, folks. The interface -- especially on the touch-calibrated editing suite -- is slick and attractive, and Tadaa also features a growing social photography community. Check it out. Tadaa is <a href="http://itunes.apple.com/us/app/tadaa-hd-pro-cam/id410005685?mt=8" target="_hplink">free on the iTunes App Store</a> .

  • EyeEm

    EyeEm encourages sharing photos of a similar type: There are groups for photos of New York, and for photos of coffee, and for photos of French fries; that means you can take a picture of your French fries, show other people who photograph French fries what you've done, and then look at photos other people have taken of French fries. Or, you know, whatever -- maybe I'm just hungry for French fries. The camera itself also features filters and a good selection of borders to hipster-ize your work. Logging in through your email or Facebook is required. EyeEm is free in both <a href="http://itunes.apple.com/us/app/eyeem-photo-filter-camera/id445638931?mt=8 " target="_hplink">the iTunes App Store</a> and <a href="https://play.google.com/store/apps/details?id=com.baseapp.eyeem " target="_hplink">the Google Play Store</a>.

  • Camera+

    One of the most popular third-party cameras for iPhone, Camera+ is probably most well-loved for its well-designed, easy-to-use Lightbox editing suite. Lucky for those fleeing Instagram, that Lightbox also contains a huge set of filters and borders. It doesn't come with a social network of its own like Instagram does, but if you're looking for an excellent camera first with Instagram-like filters second, Camera+ is a safe, attractive choice. Camera+ is <a href="http://itunes.apple.com/us/app/camera+/id329670577?mt=8" target="_hplink">$0.99 in the iTunes Store</a>.

  • Hipstamatic

    Hipstamatic takes the Instagram/Kodak connection to the next level: Where Instagram borrowed the filtered look from the venerable photography company and ported it onto the iPhone, Hipstamatic borrows the whole dang camera. Shooting with the Hipstamatic camera, you choose your film, your lens, and your flash -- the different combinations result in different effects. The standard app costs $1.99 and comes with three different flashes, and film rolls and four different lenses -- you can buy more of these with "Hipstapaks," available to purchase inside the app. It's fun to use, if only because it might be the only camera for the iPhone on which you have no idea what your final product is going to look like until after it is "processed." Hipstamatic is $1.99 <a href="http://itunes.apple.com/us/app/hipstamatic/id342115564?mt=8" target="_hplink">in the iTunes App Store</a>. If that's too mainstream for you and you're looking for a free alternative (BONUS APP), check out Retro Camera Plus <a href="http://itunes.apple.com/us/app/retro-camera-plus/id403503545?mt=8" target="_hplink">in iTunes here</a> and <a href="https://play.google.com/store/apps/details?id=org.urbian.android.tools.vintagecam&hl=en" target="_hplink">for Android here</a>.

  • THE HUFFINGTON POST

    Companies insist Instagram will stay the same after Facebook's biggest acquisition ever.