I can log as many chemical adds as I want and use the built in math and everything, the issue is trying to log test results. Unless I go in and delete my prior test results it says you can only have one log at a time unless you subscribe. Only just got the app so I don't know about subscribing this fast, just wondering if this is how it functions. I push the + for the New Log in the middle, I hit Log Test Results and it says I need a premium subscription for that. If I go into log history, delete the prior test results, it lets me enter new test results.