tapas needs to work on their app. Free comics are hard to find on it. They said they'd work on it in a different thread but that was a long time ago. It's no surprise new users think tapas is a full paid platform this way. I just continue to hope they'll do something eventually.
Edit: There is a community tab, but that shows just a few free comics, I dunno what they're based on though.
That said, premium comics aren't that expensive :3 especially compared to other sites, if a story got you hooked and it's worth to pay for I think it's worth it, some people can't afford it even if it's cheap or are unable to make online purchases, but a lot of the premium comics are 'pay or wait' which lets you read a new episode every week or so, which is nice.