GlockApps only checks your sending IP address(es) against 50+ popular blacklists and shows you where your IP is listed. If GlockApps determines the blacklisting issues for your IP, you can click on the red box in the Black Lists column and see the detailed report about the IP status. You will see the links to the blacklists’ websites where your IP is listed. Go to the websites to read more about the listings and find the de-listing process.
It makes sense to get it unlisted if you are sending emails from a dedicated IP address. If you send emails using an email service provider, you are most likely on shared IPs. Email service providers take care of blacklisting issues themselves if their IPs get to major blacklists that really impact the Inbox placement.