You may have used https://kenkoooo.com/atcoder#/table/ to check for Atcoder Problems and their difficulties. I like this tool so much that I decided to write a CF version of it (I have got permission from the author to copy the exact same style of his website).
It has been posted on my blog https://tom0727.github.io/cf-problems/.
Here is a preview of it:
If you encounter any problems using this tool, or you have a bad experience using it on phone, please inform me, thanks!
• This list is updated automatically every day.
Update1: It is a good idea to add Login function and track AC status of the problems. I will work on this feature recently. For other features, since this page is written in pure html/css/js, it might be costly to add new complicated features. Therefore I plan to refactor this project next year if there are many people using it.
Update2: Added Login Feature! You only need to input the handle, password is not needed! Also when you mouseover a contest name, the whole name can be shown. Enjoy!
Update3: The contest names are shorter now, the rendering logic has been changed to make the page faster.
Update4: Fixed a bug where some new contest problems have rating "undefined". Now the list will not contain any problem that does not have a rating.
Update5: The tool is now updating automatically everyday.