You're right about how important face-to-face interaction is. That is not going to be replaced any time soon - nor should it be. But for the purpose of handover, you still need a written summary of all the patients on a ward that people can refer to. As I mentioned in the post, it would be useful to see who wrote what about each patient - so that you know who to talk to for further information. Having a handover application won't replace the morning handover meeting or a person-person handover - but it will definitely make that process less painful, more accountable and much more efficient.
(P.S. if I was jealous of the so called riches of being an entrepreneur - I would have focussed my energies on my medical career and right now I'd be driving my A5 from work rather than sleeping on a friend's couch thousands of miles from home :) I don't think anybody who takes this path should be under any illusion. Most start-ups fail and it's not an easy path. That said, I do love a lot of what building a company involves...)