  We present the first public code for semi-analytical calculation of the
gamma-ray flux astrophysical J-factor from dark matter annihilation/decay in
the Galaxy, including dark matter substructures. The core of the code is the
calculation of the line of sight integral of the dark matter density squared
(for annihilations) or density (for decaying dark matter). The code can be used
in three modes: i) to draw skymaps from the Galactic smooth component and/or
the substructure contributions, ii) to calculate the flux from a specific halo
(that is not the Galactic halo, e.g. dwarf spheroidal galaxies) or iii) to
perform simple statistical operations from a list of allowed DM profiles for a
given object. Extragalactic contributions and other tracers of DM annihilation
(e.g. positrons, antiprotons) will be included in a second release.
