Remove featured image from the post

I would like to change something about the way WPtouch looks but I can’t figure out how to change it. My main page displays all my posts with the featured image as a thumb, which is fine. However, once you click on the post and open it, it displays the featured image on top of the text of the post, I do not wish the featured image to be seen there, how do i delete it?

https://ww.wp.xz.cn/plugins/wptouch/