How to change measurements from displaying feet and inches to mm in LibreCAD Ver 2.13

Hi folks,
I am new to LibreCAD.  I downloaded LibreCAD ver: 2.13 on to my iMAC and it is a super CAD software.
It works perfectly except the measurements display on my screen in Feet and Inches.
Can anyone help me to change the mesurements from feet to mm please. Also what is the latest version which is compatible with OS X Capitan 10.11.3?

Thank. Larry
 

To setting default :
Go to Options --> Application Preferences --> Defaults --> Unit --> Millimeter



To setting on your current drawing session :
Go to Options --> Current Drawing Preferences --> Units --> Main Drawing Unit --> Millimeter