I didn't have any trouble getting it set up - for those who can't find the free option, go to the breadcrumbs all the way at the bottom of the home page and click on Visual Voicemail.
It's a bit funky to set up - took about 15 minutes, but no issues.
Go all the way through set up on the website, including the set up my phone page. Call the long call forwarding number they give you, then test it out on the website. THEN go and get the app and log in to that, there was no set up with the app, worked well.
However, it seems you can't change your PIN on the free version - at least I can't find the option to. That may be enough to get me to cough up $5 a month. Grrr.