Short answer: no! The Sing! app is available for the two major mobile operation systems: iOS and Android. There are no versions for desktop operating systems like Windows, MacOS, Linux or other mobile platforms like Kindle or Windows Phone. 

However, people have successfully used the Sing! app on PCs using Android emulators like BlueStacks. This simulates the use of a mobile operating system on your PC. It might not be as stable as the use on a mobile device though and you might run into compatibility problems in regards to your microphone or video camera.