The only customization options you have in Windows Phone 7, are, by default, pretty limited: You can choose between black and white backgrounds, and several different colors that are used throughout the system, for example on your homescreen. It all does look pretty nice, depending on your taste, but if you crave to customize the look of the Live Tiles a bit more, beyond different color options, you might want to give WizTiles a try.
With WizTiles, you can not only choose from several included themes, but take any picture and apply it to your tiles, like a wallpaper on steroids.
The app basically allows you to create custom tiles with their own picture, and assign specific actions to them – besides standard stuff like launching the dialer, browser, camera, etc., you can even set a tile to open a specific website, call/text/email a contact, jump into a particular marketplace section, and much more. However, due to API limitations, you can't launch third-party apps.
To save you the hassle of setting up every tile individually, WizTiles groups related tiles into themes, which already include all the necessary graphics. Several themes by the community can be downloaded from within the application, but should you choose to make your own theme, there are two options: if your needs are simple, just head over to the WizTiles Designer website (pictured above). There, you can upload an image, and the site will create a ZIP for you that can then be imported into the app.
If you want more control over layout and graphics, you can refer to a forum thread for more instructions – however, if you don't feel like tinkering too much, this is completely optional.
And, best of all, WizTiles doesn't even require your device to be unlocked – it's available as a free download in the marketplace. Don't let the price tag fool you, since the trial is perfectly funtional, albeit without some nifty features such as automatically updating of themes.