We made this app recently for our friends at Barcelona Creations to help hospital staff have access to the medical calculators they need on a daily basis.
The app is separated into several medical categories and within each category you can find a range of medical calculators that apply.
The app uses a single code base for publishing both a full and lite version. The lite version features a restricted feature set and AdMob banner ads.
The app also supports multiple languages and features a php driven feedback system for users to request new features etc.