Unable to find an app in the App Store
You can try visiting the developer's website and click the App Store link for the app. Searching for the app on the Web can also fetch you the App Store link.

If you have previously downloaded the app and are not able to find it anymore on the App Store, there's a possibility that either the developer of Apple has taken the app off the App Store or the same is no longer available in your region.

The best way to resolve is to get in touch with the developer via their website.