Are you looking for some free apps? 30,000+ users downloaded Radiation calculator latest version on 9Apps for free every week! You can enjoy it by use in your own phone. This hot app was released on 2017-11-27. However, has been a fashionable app for a long time.
The app calculates dose rates etc. assuming a point source in vacuum and linear attenuation in shielding materials. Isotopes and shielding materials can be added, deleted or modified.
The predefined gamma rate constants and attenuation coefficients were found on the web. I do not guarantee correct predefined values.
Very small bug fix!