User Interface designer for Windows app (must have C knowledge)

We do have a windows application which has an old and boring design. We now need to make this interface more user friendly, enhance the workflow and more modern: You need to do: - analyze competitors application - analyze our application / understand what it does **I will provide more details on the applications / competitors to bidders. - group functionalities better than it is now. Todo: - Come up with a user interface design that works well and combines the best approaches of our competitors Note: - Additionally this user interface shall also be working in a similar way in a web based application. Our application is written in C++ / Delphi - to be able to convert the design for our application, it is required that you / your team has a developement background. **Pls send screenshots or refernces to applications you have designed / worked on