How to see which countries the app is allowed? I am trying to find where I can install Epokrates Plus app. In Finland, it is not allowed. 
Having my devices, I see in all: 


  This app is incompatible with all of your devices.


I tried to send email to the developers but I could not, since Email page just kept loading, and did not let me pass through. Either they are geoblocking or having server downtime.
Sensor Tower overview says USA, Canada, Brazil form 90% of user base remaining being others.
Sensor Tower Reviews shows Mexico and Saudi Arabia. 


That makes it 6 countries, including India (I see it on Play Store). You could write to them and check for a full list.

Edit: I mailed them using Play Store support mail, linking this question and they reverted very promptly. Non availability in some countries is because of GPDR issues. Details pasted in chat.