It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)
There are three routes;
- Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
- Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
- Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.
The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.
If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.
The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.
If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.
I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.
Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.
Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase
Add a CFBundleIconFiles key of type Array to your Info.plist. The array should contain 2 string items: the filenames of the two icons. The OS will then automatically choose the correct icon for each platform based on their pixel dimensions.
You can keep the CFBundleIconFile key and have it point to the icon file for the iPhone for 3.0/3.1 compatibility.
Update May 2010: Apple now has Technical Note explaining this in great detail: Technical Q&A QA1686 – App Icons on iPad and iPhone
Best Answer
You can make four icons (as of today) for your app and they can all have a different look - not necessarily based on the 512x512 image.
If you do create a set of custom icons, you can set the
UIPrerenderedIconoption to true in your info.plist file and it will not add the gloss effect but it will place a black background under it and still round the image corners with these corner radii so if the corner radius on any of the icons is greater then it will show black around the edges/corners.Edit: See comment from @devin-g-rhode and you can see that any future icon sizes should have a
1:6.4ratio of corner radius to icon size. There is also a very good answer from https://stackoverflow.com/a/29550364/396005 which has the location of image mask files used in the SDK for rounding icon cornersTo add a retina-compatible file, use the same file name and add '@2x'. So if I had a file for my 72x72 icon named icon.png, I would also add a 114x114 PNG file named icon@2x.png to the project/target and Xcode would automatically use that as the icon on a retina display. You can see this in action on the Summary page of the application target if you've done it right. The same works for your launch images. Use launch.png at 320x480 and launch@2x.png at 640x960.