Question:  How do I access the apple TV app store without buying a 4th gen apple TV?

I am considering purchasing a 4th generation apple TV.  However, I would only purchase one if there were a compelling reason to upgrade from my 3rd generation apple tv.  So far, nothing I have seen in the fancy marketing materials is even remotely compelling to me.  What would be compelling is being able to confirm if a small handful of apps that I would like to use were available in the apple tv app store.  However, I have not found anyway to access the apple tv app store, short of buying a 4th gen apple TV.  Which, again, I won't do if I can't see the apps available.  I have more than one of every other apple product made.  I would be happy to view the apple TV app store on my Macbook Air, or one of my iPads, or one of my iPhones.  Or even one of my 3rd gen apple TVs.  Just not going to buy a 4th gen until I see the app store.  Question:  How do I access the apple TV app store without buying a 4th gen apple TV?