I’ve read your brief and can see that you’d like to build with quick turn around. My team has 5 years experience designing and developing apps for both web and mobile.
I would approach your project by starting with wireframes and getting the design completed, before starting the actual development phase. I am highly qualified for this project and would love to speak with you further about taking this project on. If you'd like to view my previous work, take a look at my Freelancer Portfolio