What is BlastSim? BlastSim is a free app for calculation of area affected by nuclear explosion based on formulae researched by Nuclear Explosion Archive. The software is intended for users who wish to know more about devastating effect of Nuclear explosion and maybe useful for evacuation planning. This app makes it easy to calculate affected area for just a few taps. This app can be use to experiment with range of thermal radiation, radius of radio active fallout and possible number of casualties. It includes list of popular weapons in human history, such as Little boy, Fat man and Tsar Bomba. It is also possible to input custom yield of the weapon (in kilotons) List of formulae/reference papers used are on our website. Which can be access from the menu section in the app.