- Sharing buttons.
- Follow buttons.
- Like and reblog buttons below each post (inside blog).
- And set up comments.
- And widgets of your twitter profile or your facebook page (on the side of your blog).
- Traffic tracker widget.
So that your Tumblr looks more seriously nicer and more professional and will get you traffic to your Tumblr.
And your ordinary boring theme like this one ---> http://goo.gl/6NJf17
will be transformed into socialized and functional as this ---> http://goo.gl/NR5UeY theme.
Note: You will be required to leave your login information, which you will later change (passwords) when your modification is complete, on your Tumblr.