I started using Tapas on desktop before I got the app and before coins were introduced to desktop, and it was hard to find premium comics back then. I agree that it's harder to find non-premium comics on the app since I use desktop to find new comics and I usually use the app to read what I have in my library. I get why people are turned away from Tapas.
But yeah they need to improve their tag system and make searching for things easier.
I also wish that they'd move the new and noteworthy stuff to the top too, since they're there for a week anyway, but premium is up forever. It'll also be nice if they kept the lock symbol on locked episodes to make it clear that they are locked. They should also put a little symbol on premium comics too, especially on desktop, because you can't tell if it's premium until you click on it.
They introduced a feed thing into the app recently to help you 'discover' new comics. The problem is that I've already seen most of those recommended, and over half of them are premium.
I swear they used to give out bonus coins, not just for subscribing to comics. What happened to them?