My friend Alex created a Facebook app for his celebrity look-alike startup, FaceDouble. FaceDouble lets you submit photos via the Web, cell phone, or Facedouble to see what celebrity you look like, as well as vote on submissions from others. Take a look, it’s a lot of fun to play with. His Facebook app is at http://apps.facebook.com/facedouble .

In all it took him 7 days to get the Facebook app created (he already had his regular site up and running). He submitted it for approval on Saturday, got it approved on Sunday, and today (Monday) he’s on top of the mobile and dating categories. He went from zero users to 500-odd user in about a day, and seems to be adding about a user per 1-2 minutes, although it slows down significantly during US night hours.

To be sure it’s not simply putting the app on Facebook that’s driving the usage – the stand-alone app itself has to be compelling. On Facebook, the app is tailored to take advantage of the social aspects – it’s integrated with Facebook albums and photos, allowing you to Facedouble your friends and send them the results all within the app.

His take on Facebook vs Myspace: he spent close a month getting his Myspace page working “fighting the formatting – you spend all your time trying to work around the restrictions and road-blocks”. He’s not terribly pleased with the results – he had to create a bot to accept all the friend requests, and the take-up is not nearly as fast as with Facebook. Part of the problem – “the Myspace users don’t understand you can use the product as opposed to just look at the page.”

He’s quite happy with the Facebook API:

Facebook’s done a smart job with the APIs – they’re giving you exactly what you need to get your work done. The combination of Flash, iframes, and FBML gives you just enough to let you do anything you want to. There hasn’t been a single situation where I’ve run into a roadblock that there wasn’t a reasonable solution for.

He’s also pleased with another aspect of FBML:

You get the Facebook look and feel without effort. Your app feels integrated into Facebook, as opposed to a separate, disjoint app.

He does have some concerns about the unchecked growth of apps on Facebook. From his post on the “Dear Facebook: Stop Becoming Myspace” group:

Facebook applications aren’t inherently bad, they just don’t have enough peer review, and the novelty is making many of my friends expose me to content that isn’t interesting at all. It’s similar to all garbage I get from those same friends over email. I came across this site:

http://www.facereviews.com

The facebook directory is just garbage and is so full of junk now, that its lost its value. I’m probably only going to add apps that have been reviewed properly by third parties. (I use the same strategy before I install any s/w on my desktop computer too, same concept really)

I’ll be posting updates on how the app grows. Let me know if you have particular questions or areas of interesting and I’ll look into them.

Now he just needs to create an iPhone app to get the maximum buzz!