Mobile phone app programmer

I have an idea for a new application that I need built that will run on both iPhones and Android phones. It's a small and discrete application, but it requires an integration with other services and so I need somebody who is an experienced application developer who can put it together. I am a 30-year veteran of technology growth companies, so the right person can do well here and demonstrating success can lead to much more work going forward for this and other related tech projects.
Requirements: Below are non negotiable. You must possess all of these for this to work successfully.
1) Knowledge of building dynamic websites with customer workflows (both front end and back end).This is required to sign people up to the service, on board them, and bill them.
2) Experience building easy to use graphical mobile applications that can run cross-platform.
3) Experience with product review and service review sites like Google, Yelp, and others.
4) Strong English written and spoken communication skills.
I have helped take 2 companies public in the US. Let's join and build another.