Based on the original print booklet, the Wallet Cards app is a comprehensive source of information on all known nuclei.It contains data on ground and isomer states for each nuclide, as well as the following observable properties (where available):- excitation energy- spin-parity- half-life OR decay width- mass excess- natural abundance- observed/predicted decay modesUsers can search for nuclides by atomic number (Z), neutron number (N), or atomic mass (A).Users also have the option to search for specific ranges of the observable properties shown above (i.e. "half-lives greater than 5 years").Produced and maintained by the National Nuclear Data Center (NNDC) at Brookhaven National Laboratory (BNL).