Unless they haven't updated the Android app, it's still showing this as a premium feature. I've installed it and it says "Your LastPass Premium trial will expire in 60 days".
I would think if it was truly free now then I wouldn't be seeing this message.
their free service also requires you to sign in every month. I'd suggest a service like http://freedns.afraid.org/ which is completely free and doesn't require monthly logins to keep your account active.