What is the world best pure checklist app?

[appinitpro]

I just want to have a pure simple, clean and intuitive checklist app for my daily work. Any recommendation?

I found Check List++ Pro is a best app I have ever found, but I don't know if it's really the world best app for a pure checklist.

https://itunes.apple.com/app/check-list++-pro-world-most/id647752503?ls=1&mt=8

Any great free app should be awesome.