2025-04-29 00:00:00 What is BlastSim? BlastSim is a free app for calculation of area affected by nuclear explosion based on formulae researched by nuclear explosion archives. The software is intended for users who wish to know more about devastating effect of nuclear explosions which is useful for evacuation planning. This app makes it easy to predict possible affected areas for just a few taps. This app can be used to experiment with the range of thermal radiation, the radius of radioactive fallout and the possible number of casualties. It includes a list of popular nuclear weapons in human history such as Little Boy, Fat Man and Tsar Bomba.