NSLog

In the app settings, there is an option to enable NSLog so that all tracing can be found with cfgutil

When enabled, all logging can be viewed on a Mac:

• install Apple Configurator 2 on a Mac (it's not necessary to run the application)
• Open a Terminal session (on Mac click Search button top right, type 'Terminal', double click on the Terminal app)
• change directory to Downloads folder , type : cd Downloads
• copy paste this : /Applications/Apple\ Configurator\ 2.app/Contents/MacOS/cfgutil syslog | grep xDrip-NSLog | awk -F "xDrip-NSLog " '{print $2}' > xdriplog.txt and press enter

Now use the app, all logging information can be found in the file xdriplog.txt You can also leave out the redirection to file.