That's a well done question. Here's the prior answers.
-> https://www.google.com/search?q=How+to+create+responsive+Wordpress+Theme
How to create responsive Wrodpress Theme.
I need responsive Image site theme in Wordpress . the site is [****removed by modertor]
**** Note. Top posts like these must be URL free for basic questions that are well done.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic