USSDSpace is a proof of concept macOS application that allows a non technical user to define USSD menus and actions using a GUI interface and deploy these menus to a Java based server for interfacing to a cellular service provider's USSD service I have yet to see an application that allows this, although there may be one out there. This was initially written in Swift 2.3 and makes heavy use of CoreAnimation and Cocoa. This repo also contains a basic implementation of a Java servlet based receptable for the USSD graph definition. I have tested this using Vodacom's USSD service.
If anyone is interested in exploring this concept with me, let me know, I think there may be a usable concept here.