Focus

From $19 (about £15) FROM

Brad Jasper, heyfocus.com

NEEDS OS X 10.10 or later

Apple’s Screen Time is good, but Focus goes further. For instance, while Screen Time lets you limit social media websites, you can always just ignore or delay the limits. Focus, though, has a Hardcode mode that can’t be overridden. Perfect if you need to be strict with yourself.