Rough Draft - Mobile App Architecture

This is very rough, but we need to start thinking about how the various modules and parts of the Mobile App will work together and be presented as a whole. 
Most details about individual modules, besides OPD, are unknown. If you're working on modules such as IPD, Lab/Tests, Pharmacy, and any other modules that have not yet been made,
please add details about the flow of the screens/pages in the comments section.