Originally I developed this icon tool to help people to quickly build windows store and windows phone apps using the Web Application Template which is a tool designed to wrap web content and allow it to plug easily into native app features such as live tiles, settings and social sharing integration. (I have another post here which shows how to quickly wire up push notifications using Azure). I prototyped quite a few of these apps and one pain point was creating the icons as often I didn’t have any vector art available and there are quite a few size variations to create. The first time I found a bitmap and resized it ‘by hand’ in a paint package but this was not a task I wanted to repeat so I automated it with some C# code.
Choose an input image with as high resolution as you can find as the resize filtering will cause the icons to look increasingly more blurry as they are enlarged.
The tool generates a zip file containing all standard icons for the platform that you choose (from Windows Store, Windows Phone Silverlight or Windows Phone WinRT). You can extract the icon files into your project folder where the default icons are and it will overwrite some existing ones and copy over all of the other options for different icon sizes and the splashscreens and also promo images for the store. (Note that you would need to wire up the additional icons in the app manifest). The original image will be centred and you can adjust the padding around it and also select a background colour (it will default to the pixel colour at (0, 0) if this is left blank.
Let me know if you find that any images\platforms you require are missing.