A free and open source desktop app for browsing isotope and nuclear structure data in the Chart of Nuclides / Segrè chart format. Uses nuclear structure data from ENSDF, masses from AME2020, and isotopic abundance data from NIST.
A full list of features is here, and a user manual with detailed documentation is here.
Get the latest release and follow the installation instructions there.
Alternatively, the application can be built from source using the instructions here.