Twitter has tremendous utility for the medical community. I am final year medical student and through twitter can follow worldwide leaders in emergency medicine (my field of interest). These doctors post clinical factoids, cases reports, unique ekgs, and other learning points live from the wards (all de-identified to protect patients of course). They also post opinions on the latest research publications. Twitter has become my best way to stay current in medicine.
Other apps targeted for doctors have attempted this. Doximity and Figure1 are examples. But twitter has done the best job.