  The Laser Interferometer Gravitational Wave Observatory (LIGO) and Virgo
Collaboration's Observing Run 3 has demanded the development of
widely-applicable tools for gravitational wave follow-up. These tools must
address the main challenges of the multi-messenger era, namely covering large
localisation regions and quickly identifying decaying transients. To address
these challenges, we present a public web interface to assist astronomers in
conducting galaxy-targeted follow-up of gravitational wave events by offering a
fast and public list of targets post-gravitational wave trigger. After a
gravitational wave trigger, the back-end galaxy retrieval algorithm identifies
and scores galaxies based on the LIGO and Virgo computed probabilities and
properties of the galaxies taken from the Galaxy List for the Advanced Detector
Era (GLADE) V2 galaxy catalogue. Within minutes, the user can retrieve,
download, and limit ranked galaxy lists from the web application. The algorithm
and website have been tested on past gravitational wave events, and execution
times have been analysed. The algorithm is being triggered automatically during
Observing Run 3 and its features will be extended if needed. The web
application was developed using the Python based Flask web framework. The web
application is freely available and publicly accessible at
gwtool.watchertelescope.ie.
