I'm trying to move a metro app from my old Windows 8.1 PC to my new Windows 10 PC. Before you say 'Just re-download it' I should point out that, for some reason, MS have not only pulled it from the store but it also doesn't appear on my list of apps that are available to download. The only place it appears now is in my purchase history.

Therefore, if the app is not to die when my old PC dies, I need someway to back it up and move it.

I've seen programs that back up app data, but can't see anything that backs up and restores the app itself.

Any ideas?