I have been using GC for quite a while, both regular and development builds and 3.1 is a huge move forward in look and feel, with many new features. I think this may put it into another league and very comparable to just about any fitness tracker. They also have tutorial videos etc, very professional! Well done GC people! Take a look here: http://www.goldencheetah.org/#section-download
(in case you wonder I have nothing to do with GC just a big fan of the software)