But, if you're using any custom blogger template.. you may not see the widget appearing in blog..even though you activate it.
So, if you have that problem. here is how to fix it.
(before making any changes..first backup your template)
1. Sign into Blogger > Design > Edit html
(tick the expand widget templates)
2. Add this line anywhere you want the widget to appear
<b:include data='post' name='shareButtons'/>
Normally, in most templates, you can add it after this line..
<p class='post-footer-line post-footer-line-1'>
If you don't find that above line in your template....
Find this one.
and add this code after that line..
<div style='clear:both; padding: 10px 10px 10px 10px;'> <b:include data='post' name='shareButtons'/> </div>
Note: If you're using Magazine style blogger template, You can find the data:post.body line TWO TIMES.. So, try in both ways and find out which one is working..and remove the other one.
Finally..Save the template!
If you still don't see it in your Blog, Make sure..you activated it by going to
Blogger dashboard > Design > Click the 'edit' button of the Blog post section.