Is there a way I can use non-post content in this plugin?

Yes. You can use one of build-in filters:

To replace whole box:

add_filter( 'iworks_upprev_box', 'iworks_upprev_box_mycontent' );
 
function iworks_upprev_box_mycontent( $content )
{
    $value = '<div id="upprev_box">';
    $value .= '<h6>My own title</h6>';
    $value .= '<div class="upprev_excerpt">';
    $value .= '<h5>Lorem ipsum</h5>';
    $value .= '<p>Lorem ipsum dolor sit amet, consectetur ';
    $value .= 'adipiscing elit. Vestibulum auctor neque vitae orci ';
    $value .= 'ornare et vehicula eros molestie.</p>';
    $value .= '</div>';
    $value .= sprintf(
        '<a id="upprev_close" href="#" rel="close">%s</a>',
        __('Close', 'upprev')
    );
    $value .= '</div>';
    return $value;
}

Get code: iworks-upprev-static-content.php.zip

Where to put this code?

There are three ways:

  1. made a one-file-plugin and put file into wp-content/plugins, then turn it on
  2. made a one-file-plugin and put file into wp-content/mu-plugins
  3. put this code into functions.php in current theme

I recommend using option 1 or 2, but 3 is the easiest.

How to change post thumbnail to other image?

Use the iworks_upprev_get_the_post_thumbnail filter:

<?php
add_filter( 'iworks_upprev_get_the_post_thumbnail' , 'change_thumbnail' );
function change_thumbnail( $image )
{
    return '<img src="image.png" alt="" />';
}

Read more: Filter Reference / iworks upprev get the post thumbnail

Where to put this code?

There are three ways:

  1. made a one-file-plugin and put file into wp-content/plugins, then turn it on
  2. made a one-file-plugin and put file into wp-content/mu-plugins
  3. put this code into functions.php in current theme

I recommend using option 1 or 2, but 3 is the easiest.

3.2

  • IMPROVMENT: added action iworks_upprev_image – you can add own code to produce icon, when them don’t support post-thumbnails
  • IMPROVMENT: added thumbnail filter iworks_upprev_get_the_post_thumbnail – now you can easy change thumbnail
  • IMPROVMENT: added purging transient cache entries from $wpdb->options table when turn off this cache forum
  • IMPROVMENT: add check _gaq object exist
  • CHECK: checked compatybility to WordPress 3.3
  • IMPROVMENT: updated IworksOptionClass to version 1.0.1

3.0

  • BUGFIX: fixed end date filter for imported posts
  • BUGFIX: fixed javascript conflict on edit post screen
  • BUGFIX: fixed problem with unchecking ‘Excerpts’. forum thx benjamin
  • BUGFIX: fixed sticky posts display loop
  • BUGFIX: fixed thumbnail display problem
  • IMPROVMENT: added filter ‘iworks_upprev_box_item’ for any item excerpt YARPPs
  • IMPROVMENT: added GA track: view box and click link
  • IMPROVMENT: added option ignore sticky posts
  • IMPROVMENT: added sanitize function for offset
  • IMPROVMENT: added thumbnail preview on posts/pages list
  • IMPROVMENT: cleaning empty styles from custom css field
  • REFACTORING: option managment

2.3

  • IMPROVMENT: added filter iworks_upprev_box
  • IMPROVMENT: added tabed options (based on Breadcrumb NavXT plugin
  • IMPROVMENT: added prefix and suffix to urls
  • IMPROVMENT: added option to allow open links in new window
  • IMPROVMENT: added integration with YARPP
  • BUGFIX: fixed Transients Cache Lifetime is set to wrong seconds
  • BUGFIX: fixed deactivation hook option names

2.0

  • IMPROVMENT: added to use transient cache
  • IMPROVMENT: added thumbnail width (height depent of theme thumbnail)
  • IMPROVMENT: added prevent some options if active theme dosen’t support it
  • IMPROVMENT: added activation & deactivation hooks (to setup defaults and remove config )
  • BUGFIX: remove all filters the_content for post in upPrev box
  • BUGFIX: fixed display upPrev box in case of an equal height of the window and the document