I just paid for the pro version, uploaded it to the plugins folder, and tried activating it both network-wide and in an individual member site. Both times it doesn't work at all, and just causes this error message to appear at the top of whatever page I'm viewing:
Warning: Warning: Missing argument 2 for wpdb::prepare(), called in ../wp-content/plugins/wti-like-post/wti_like_post.php on line 302 and defined in ../wp-includes/wp-db.php on line 992
I tried Googling the error and found this: http://make.wordpress.org/core/2012/12/12/php-warning-missing-argument-2-for-wpdb-prepare/
Is the Pro version untested and buggy, or at best a security risk? In that case, lol, how do I get a refund? It's not worth it for me if I'm going to end up on the support forums 20 times... It's the first time I've tried using a paid "pro version" of a plugin, so I'm a bit disappointed.