Marlboro

If you mean the Marlboro tobacco app, it's a web app. Go to Marlboro.com on your iPhone. As you scroll toward the bottom, you'll see a banner pop up that asks is you want to put the web app on your phone. I did not test what happens at that point as no, Marlboro does not need my help.

Best of luck.

If it is not in the App Store when searching, then the App is not available in your region.