ModRana is a flexible GPS navigation system for mobile devices. This is the main upstream modRana source code repository - waiting for your pull requests & patches! :)
The espeak binary has quite a few command line options that might be of interest for users to tweak and could be especially handly in more complex non-English scenarios.
So it would make sense to expose these options in the GUI so that users can override the default options and use custom ones and to store the custom options persistently.
BTW, IIRC modRana should have something like this available via the classic GTK GUI, the same backend mechanism might possibly be used also from the Qt 5 GUI.
The espeak binary has quite a few command line options that might be of interest for users to tweak and could be especially handly in more complex non-English scenarios.
So it would make sense to expose these options in the GUI so that users can override the default options and use custom ones and to store the custom options persistently.
BTW, IIRC modRana should have something like this available via the classic GTK GUI, the same backend mechanism might possibly be used also from the Qt 5 GUI.