lastpass not free? Rated 1 out of 5 stars

Twice I have downloaded Lastpass for my android tablet after reading that it was "free", then after a few weeks it tells me that my "free trial" has expired and I need to purchase it. Why is it not stated that is only a free trial, and why is it free for OS and not for Android?

This review is for a previous version of the add-on (2.0.20). 

LastPass is free for the desktop, paid on mobile, that's our freemium pay wall.