[Help Needed] How to Read Online Materials , Tutorials with FOCUS?

Hi Coders,

I wanted to ask for tips that will enable everyone to read articles,tutorials and concept online with more concentration.

I wanted to know if there is any online site that will help in maintaining good screen reading Speed

This will help individual to be more productive by grasping concepts easily.
Also it would be great if someone could share some EXTENSION that might help.