Dear developers: Why not support both iPhone and iPad?

I think the best thing to do is goto touch.facebook.com on the ipad and put a shortcut on the home screen. Boom, iPad facebook app.

Agree with @Meat.

UI development is by far where the heaviest lifting takes place.

Also, some app concepts naturally lend themselves to small or large screen factors.
I recently spent 4 months developing a purely iPad app simply because the UI could not work very well on a small iPhone screen.

Now, in the case of Facebook, this is not the same.
There is already out there a pretty decent native iPad Facebook app and I'm sure others might follow.

Suggesting that web apps work nicely on the iPad, hence no need for native apps, is a bit naive. There is absolutely no way a web app can ever do a better UI job than an equally good native app. It is not possible, simply because native apps have unfettered and complete, low level access to all parts of the system (e.g., when is the last time you saw a web version of Gran Turismo ?)

Apple is dead right in suggesting that the future lays in a world of web 2.0 services backbone coupled with native app clients.

It's a common misconception for non-developers to think that "writing the app" takes up bulk of the time. For an app that aims for even a mildly decent UI, it is UI development that takes up bulk of the time. So doing it for another fo factor, really does take a lot of time. It's not the minor adjustments, that it appears to be. Sure one can simply scale th UI up or down, make minor adjustments and call it a day. But the results of doing that will simply not be optimal. You may have more potential customers but the poor reviews due to the bad UI will actually lead to lower sales. So it is usually better to optimize for a single device form factor first and then do the other device later.

This is all very interesting conversation. I appreciate everyone chiming in.

1) I find the idea of Facebook not having an iPad app because of political positioning in the industry or whatever-it-is makes me want to puke.

2) I can't expect small devs to support everything right away, but that's much less of an excuse for huge companies who are trying to sell things for iOS users. If a huge company doesn't have the resources to update their iOS app to support the iPad's screen, I think there might be a small problem.

3) The Facebook website is fine, but the important thing is push notifications. I hate having the iPhone version installed for notifications while using the web interface.

4) I appreciate that optimizing the UI might be more of a process than I led on in the post, but it certainly can't be harder than making the application in the first place. Yes, changing the UI takes resources, but is it such an expense that it won't be recouped by extra eyeballs on your ads or dollars in your pocket?

"After you’ve figured out the implementation, isn’t optimizing the user interface for most applications fairly simple?" -No.

A good application will spend a ton of time of the design and user interface for a specific device and it's capabilities. Think of it this way, ask someone to repaint the Mona Lisa on the side of a building. It's still gonna be the woman sitting in front of a background, but they're gonna have a ton of area to add new detail, might take the artist a long time to decide how to add details.

Now go in reverse, ask the artist to paint a building sized piece of art onto a postage stamp. Details have to be cut. Entire features from the background might be missing. Mona Lisa's smile might not be 'just' right. The artist might even refuse to paint it because he can't do it correctly.

I think the reason Facebook doesn't have an iPad optimized app is that the Facebook website works fine on the big iPad screen, where as the iPhone screen is just too small for the website and is thus better off with a native app. (yes I know Facebook has a mobile version of their site, but still.)

I think that the Mark Zuckerberg said something like: "iPad isn't mobile". That could justify the lack of a facebook app...

Well, I'm starting my career on this stuff and I'm almost finishing my first application which will just on iPad. The reason is because I don't have an iPhone nor an iPod Touch and I won't release an application without testing it on a real device. And believe me, many times somethings work on simulator but don't work well on device. So, this is my point.