Oh what do I do with my Windows 8 apps in Windows 8.1 and VS 2013?

Oh-oh.

If you are an advanced developer and get to try the newest and greatest, than make sure you go to this site:

• https://msdn.microsoft.com/en-us/library/windows/apps/dn263114.aspx

And follow the instructions.  Make sure to keep a copy of the Windows 8 app separate from the Windows 8.1 app.

Or better yet, create a TFServices account and store your apps there.