Metro Studio for developing metro style app (Windows Phone and Windows 8). This software comes with 600 icons. which we can use as XMAL or PNG image file.
We have options to set image size and apply padding for image. Even we can set border like application bar icons with circle borders and we can set color for that. We can fill icon with color.
We can also use search to get images what your looking for.
Please check with image below.
At this point it is free of cost. You just need to register, so you will get a key to your given mail. Just apply that key when your it ask in setup steps.
Few more words :-
Syncfusion Metro Studio is a collection of over 600 Metro-style icon templates that can be easily customized to create thousands of unique Metro icons using an intuitive customization tool. Metro Studio is the only icon collection that you will ever need for building Metro-style applications.
We can also see those images in online here http://www.syncfusion.com/downloads/IconPackagePopup/Application