tljorgensen

Simple Post Inserter takes various inputs through the settings page and determines three things:
The content you wish to display in your posts, could be plain text, could be some HTML code. 
By default the admin of the site is responsible for any of the content submitted.
The location where the content should be displayed within the post.
Post restrictions. By default if no other setting but the content and location are declared, 
the plugin will insert the content in all of the posts available on the site. This may not be what you 
desire, but you can filter by post type, category, and ID.
Currently the only parameter for placement inside the posts is based off of total paragraphs in a post. 
This will likely change in a future update to something a little more sensible such as: lines of text or character counts.

Simple Post Inserter

Simple post inserter does what it sounds like. Insert some content into a post at your desired location.

pixelgrade

vlad.olaru

George Olaru

With <a href="https://github.com/pixelgrade/pixcodes" rel="nofollow ugc">PixCodes</a> you can have a shortcode insert interface.
The awesome part is that you can filter any shortcode parameters or overwrite any shortcode template with your theme.
Note: this plugin does not add any style to the output of shortcodes.
We believe that shortcodes functionality should be offered by a plugin and the style should be provided by themes.
Here is a <a href="http://github.com/pixelgrade/pixcodes/blob/master/README.md" rel="nofollow ugc">detailed documentation</a> about how you can configure some plugin settings and output.

PixCodes

PixCodes offers you a nice interface to add shortcodes into editor.

Simple Post Inserter vs PixCodes