It's very helpful.
I use the Whitelist option as I only want access to a couple sites while I need to study so I don't get distracted.
Noticed that I have to first activate the forest session and then navigate to websites I want to block otherwise nothing is blocked.

I also installed forest on my cellphone the only thing is, is that I can hit the home button and it doesn't prevent me from doing so. If I hit the back button to exit the app then it warns me that I'll lose my tree.