Hello,
I am a professional Software Engineer with years of experience in industry and as a consultant. I have many years experience programming in Java, C++, C#, Python, PHP, HTML, anc CSS.
As you need this software to run on a Mac I believe Java or Python would be best for a desktop application. Both of these languages provide very good libraries for designing and developing user interfaces.
Both my hours and my price are negotiable and would like to work with you to find the optimal solution as far as these two factors.
I know it is hard hiring freelancers with very little input from other employers, therefore I am willing to provide both examples of my work and links to other freelance profiles on sites where I have done more work and received more reviews.
Hope to hear from you,
Anthony