The author claims to have tried all Todo apps, and the lists only a fraction of the Todo apps available on the market. There's a reason why there are so many apps available, and without actually trying them all any conclusion is based on partial data.
i honestly don't think the author is claiming that /literally/ - it's often a figure of speech in English. My kids say it "all the kids at school <insert thing here>" - doesn't mean they meant literally every single student who attends.
