Just click "Check my Windows Phone Store" and you should be able to download the app.
If you would notice in the address bar of your browser, there should be something that looks like "/en-us/". If your phone regional settings are not set to US, then this section should be changed to your appropriate region (which clicking on "Check my Windows Phone Store" will automatically do for you). For example, my phone regional settings is "United States". Hence, if I try to load a page that has "/en-ph/" (the string for the Philippines), I will receive the same message you received even if I'm actually in the Philippines. Clicking on "Check my...." will bring the "/en-us/" version of the page and I will be able to download the app afterwards.