Short answer: there are no tools for developing an iOS app with native widgets under Windows, legally.
To develop an iOS game under Windows, you could implement your entire game in Marmalade (proprietary) or cocos2d-x (free) and then either buy a mac or have a friend with a mac let you register as a licensed apple deveoper, bring over your source code, re-build in XCode, and submit to the App store. At least in theory you could do that. In my opinion the above isn't really practical. You would have developed your entire game without ever testing on an actual device. You would have no way of testing any functionality that isn't covered by the cross-platfrom framework e.g. correct handling of device orientation and resolution, interfacing with Game Center, etc., etc.
To me, the bottomline is that if you are serious about developing to iOS, you need to buy a macintosh. Period.
To clarify, using Marmalade you can develop, sign and test on the device using only a PC. To submit your app to the App Store you need a Mac because the software used to upload the final package exists only in OS X. I've developed and distributed various games using only a PC and a borrowed MAC to upload to the store.
You have a free license that puts a Marmalade splash screen and a small watermark on the screen. The full license's price is not as prohibitive as it is on Unity though, and for me it's the best option right now for those that doesn't have a lot of bucks to spend on a license. You can also use Adobe AIR, but it's slower.