The main focus of this release was compatibility with macOS Sierra. It took us awhile to figure out why Guides and Frames always appeared at launch, but thankfully they no longer do :-)
Another issue in Sierra is the Rulers sometimes getting really small. If you were affected by this, remember that there’s a Reset Rulers option under Rulers in the menubar. That, along with Display Square Rulers, should help get things back in order.
There are other improvements which you can read about in the version history. This update is FREE for all registered xScope 4 customers.