There is a galaxy catalog which most successful teams used to identify the source galaxy of the most recently announced gravitational wave GW170817 (two merging neutron stars in NGC 4993). The optical afterglow was found as well (see the previous link).

The GLADE galaxy catalog can be found here:
http://aquarius.elte.hu/glade/index.html

It doesn't contain much more (from my amateur's point of view) than coordinates and B magnitudes. Nevertheless I can imagine it to be useful for some observing projects. If I have some time, I think I will try to add it to Guide as a custom database.