Don't expect good beer and wine. We talk about Scandinavia where that stuff is quite expensive. To me the lounge is quite ok. There are worse lounges in CPH. When I had to pay for access I usually did it only when I had to wait for more than 2 hours. Depending on the time of the day it can be crowded.
Instead of using the app you should still be able to check-in via your phone's browser and use the website.