There are tons of native apps for iphone already, no matter your ff is 1.0.x or 1.1.x. And there are tons of favorite app lists already by different people in different criteria. I don know how much you agree with them, but here’s mine. And the criteria is simple: free.
1.iCosta – the first native and system level Chinese input method. Absolutely No.1.
2.Installer – The one which makes the installation of following native apps pretty straightforward. A must, too.
3.MobileFinder – The first file system explorer and management tool. For me, most likely it works as kinda launcher
4.rSBT – The tool I used to re-arrange my springboard. Yes, i know SummerBoard. but I still prefer this one due to its simplicity and less resource requirement.
5.SMSD – Almost replaced my default SMS.app. And the author is keeping on working to make it better. I’ve talked it before.
6.Books – The ebook reader. Absolutely one of the first 3rd party native apps for iphone.
7.SwirlyMMS – The first and only MMS app for iphone until now. Even though it’s still lack of some key features like MMS receiving, it’s still worth to be in the list. And the feeling is great when I send the pictures to my friends successfully.
8.ScreenShot – A screen capture tool with GUI. Most of the pictures in this site are created by it, except the very early ones by the command tool.
9.TuneWiki – Lyrics showing while listening music. Very impressive, not only for its functions, but also for its idea of syncing lyrics by taking full use of the community. Only one thing, when can i see some Chinese song’s lyrics?
10.weDict – Dictionary, esp. for people whose mother language is not english. If you wanna know how to add your local dictionaries to weDict, read my previous post here.
One more thing, there’s some very valuable tools i didn’t cover, like jailbreaking toolkit and SSH server etc, because for most of iphone users they are transparent and hidden. Perhaps, that’s what foundation means 
That’s it. Also, hackintosh has one sticky post talking about this. You may check it out if you are interested.
