After testing so many different distraction reducing apps, extensions, etc, this is the by far the best one i have found on any platform. It is incredibly detailed and customisable, with a focus mode (lockdown mode), different block sets, time based blocks, usage limit based blocking, customisable overrides (including limits on the duration and number of overrides), blocking pages, and so much more. My only wish is they turn it into an android app with similar functionality!