The first iPhone shipped without an App Store, but with a handful of useful apps—many of which are conspicuously missing on the iPad. Here's how to replace them, for free.
The concept of nonremovable, single-purpose default apps makes a bit less sense on the iPad than it did on the iPhone, precisely because there are so many alternatives now available for download in the App Store. But this doesn't stop the iPad from feeling a bit naked without its Stocks, Weather, Alarm Clock and Voice Memo icons. Luckily, most of these can be easily replaced.
Weather: The iPhone comes with a very basic little weather app, for which there are plenty of alternatives. In fact, it's almost irritating that you can't remove it, since so many of the free apps available are actually better. The best one on the iPad at the moment is called Weather Channel Max. Maps with overlays, video forecasts, local data and warnings—it's all there.
Voice Memos: Why Apple didn't include a simple voice recording app is beyond me, because as shipped, the iPad has no software that utilizes its microphone. For now, basic voice recording can be taken care of which Voice Memos for iPad, a freemium app that roughly resembles Apple's iPhone recording app. It's free until you want to share your recordings, which requires a $1 payout for email functionality. Evernote, a more complicated journaling app, also allows for the creation of voice memos.
Stocks: Apple's iPhone stocks widget didn't do much at all. Bloomberg's free app for the iPad, on the other hand, turns your iPad into a 9.7-inch finance terminal.
Calculator: Everything has a calculator. My Mom's Nokia brick phone has a calculator. I used to have a watch with a calculator. The iPad does not have a calculator. PCalc Lite for iPad is free, and good enough.
Alarm Clock and Timer: This is the one that's most annoying, because unlike the other apps, you can't replicate the iPhone's alarm clock behaviors with a third-party app. Setting an alarm on the iPhone means that, at the designated time, your alarm will go off, whether or not the app itself is running. Third party apps aren't allowed to run tasks in the background, so any alarm clock apps would need to be left open, and the iPad's display sleep mode turned off, for the alarm to sound. Dumb.
Also dumb: there aren't any worthwhile free alarm apps available for the iPad. The only option is to (ugh) run an upscaled iPhone app. I suggest Alarm Clock Free. Some commenters are recommending a very pretty $3 app called Night Stand HD, but again, you need to leave it running, which makes me nervous. (Just use your phone! Or set a daily calendar alert!)
For basic timer duties, again, I'll have to recommend an iPhone app: Chronolite works fairly well.