This application saves no data - only settings.
To use the app features there are permissions on the phone needed.
Strictly necessary for WinDis is the use location service.
Some beta testers and I tested this application for a long time. I believe that the results are relatively error free. But I can't give you any guarantee that your values are correct. Be careful with the output and, like all good navigators, use common sense and always cross-check your data by other methods and systems.
Use the software at your own risk. The software is provided on an 'as is' and 'as available' basis without warranty of any kind.A. Fischer