The four main caliphs of Islam are Hazrat Abu Bakr (RA), Hazrat Omar Farooq (RA), Hazrat Osman or Uthman (RA) and Hazrat Ali (RA). It is the duty of every Muslim to know the biographies of these beloved Companions of the Holy Prophet Muhammad SAW.

So the developer team WikiBdApps has developed this app with the biography of the caliphs.