Get a Google-Voice number for free (or transfer yours for a one time fee of $20), download the Google Voice app and you have a better second line - with no monthly fees. With Google Voice you can receive calls the same way a regular call comes in - no need to unlock the screen and you can send and receive SMS text messages with ease. GV also sends VM transcripts via email and you have all your VMs and text messages available online for future reference. GV doesent yet offer the features provided by Line2 Business Plan (office directory for multiple lines etc.)
ChachChach about Line2 - Second Phone Number, v9.6