Respected authority,
By looking at the job requirements, it shows that you need an IOS developer as well as Android developer. Well I am an iOS developer with 3+ years of experience and my partner is an Android developer. In this way, your app will be constructed parallel. Our recent app was "Personal training coach" for android and IOS. We have worked with 10+ cloud based apps. We have worked with complex UI by giving them flexibility to change them in future.
Moving forward, we can dedicate 30 hours per week and number of our working hours are negotiable. Feel free to ask anything.
Regards.