Related Posts Widget With Thumbnail Preview For Blogger,as we all use related posts hack to show of the related posts in particular category below our posts as this helps our readers to move through our pages easily.The basic difference is that this widget adds thumbnail from that particular posts as of previous related posts widget just show of the link to post.
You can see how the thumbmnails will look in the widget in below picture.
Image and Post Source:-Techknowl
How to install this widget in blogger.
Just visit Linkwithin.
Give your Email adress,blog address and select suitable blog platform and grab the widget code.