Hello Dear, I've read your project description and I can design and build an Professional and High Quality mobile application for your business to insert your clients as per your requirements with complete mobile responsive design. Do you also want to publish the mobile app in app store?
Let's have a quick discussion about the project.
We have extensive experience in designing and developing Portals, Web and Mobile application, E-commerce in all major platforms, etc.
I am sharing our portfolio with you have a look,
https://www.freelancer.com/u/junkyfunky
Thanks,
Faizan