At last wordpress.com developed a desptop application for Windows desktop. This is not Windows Universal App. This is an Win32 application. This means you can install it in Windows 7 also.
The app is fast and the looks is identical of the website. You will feel the website has opened in your desktop application. The application supports two steps authentication.
Now you can manage your sites, write and publish, and even customize your site and view stats from a dedicated app in your Windows Start Menu. Use it for your sites on WordPress.com, as well as for self-hosted WordPress sites. (For the latter, you’ll just need to have the Jetpack plugininstalled to connect your site.)
Read more about the new Windows desktop application here.
You can download the application here.