I see how having a free demo account might be helpful for trying out the service, but a permanently free account is totally contrary to the idea of posthaven.
Really though, paying $5 to try it out isn't a huge deal if you don't like the service -- you can cancel whenever. I'd rather see development of useful features than the devs worrying about a free demo thing. Because of the way it's structured, a free trial doesn't benefit the company or paying users -- growth is not the goal, sustainability is.
Bottom line: I don't think this is the right place for people unwilling to put $5 toward an awesome idea/business model. You can go use tumblr or blogger or whatever.
But it's not a company; it's a non-profit (or is going to be one). I don't think the goal here is to get big; it's to be self-sustaining, and a free plan doesn't do that.
I would like to try Posthaven and only if I feel that its worth 5$/month to me, then I can consider upgrading from the free plan to the paid one.
A free plan is beneficial to the company, since it would help in popularizing the app.