Recently, I wrote my first Windows Phone 8 application. In order to share my application with the world, I needed to publish it in the Windows Phone app store and in order to publish it, I needed to register with the Windows Phone Dev Center. Most dev centers like this charge about $100 a year and I believe that is Microsoft’s usual fee.
But currently, they are running a special and charging only $19. This offer is good until August 27. If you are thinking of writing an app for Windows Phone 8, this is a good time to do it. You can register and pay your $19 at https://dev.windowsphone.com/en-us/join?logged_in=1.