A quick note for anybody that encounters this in the future: In many cases you can download previously purchased apps that are no longer in the App Store.
Go to the App Store
Click on your account (your icon, top-right).
Touch Apps
Touch My Apps
Search for the missing app.
This won’t always work, especially for stuff that is years old, anything from the 32-bit era will give a “Cannot Connect” error, etc. But for the most part, apps that are temporarily delisted, no longer available in your country, or otherwise not listed in the app store will be accessible.