It's your fault for downloading. Read the comments next time. If it's uninstallable, close the app. The app literally adds a few pixels to your screen.
It's not a virus, I just don't have a code-signing certificate yet. It's easy to uninstall. Just go to the 'uninstall a program' menu in Windows, and uninstall it. *After quitting it.
There's also an 'uninstall' executable in the folder it gets installed into.
In the *worst worst* case, you can just quit the app, delete the install folder, and everything will be good! (which is by default C:\Program Files (x86)\Samperson\Desktop Meadow)