It looks like you already have that app installed (probably developing on the same machine?).
Start powershell and then type this to load the appx namespace: import-module appx
Then list what you have installed and look for your application: get-AppxPackage
You will want to copy the PackageFullName and use it in the next step (in my case I am removing this app
microsoft.sdksamples.workingwithdatasourc_1.0.0.0_x86_neutral_8wekyb3d8bbwe).
Next type this to remove your app (but use your PackageFullName and not the one I show here):
Remove-AppxPackage microsoft.sdksamples.workingwithdatasourc_1.0.0.0_x86_neutral_8wekyb3d8bbwe
Jeff Sanders (MSFT)