Cross platform developer for iOS/Android - is there any good developer out there?

Can you develop apps on Corona? Titanium? any other good cross platform? I don't need lagging cross platform framework. The app we need is regarding scheduling appointments of doctors with GPS functionality enabled. This is exactly the app has to work : [login to view URL] Plattform: iOS and Android Overview: The App must have the same functionality like the website [login to view URL] plus location based search (GPS). It must use the same database like the website and data must be seamlessly exchanged. We have a couple of more apps to develop via cross platform!! Please come out some body!! Regards, PB.