Ahoy tharr, salty seadog, etc etc...
I think the consensus is that ShipFix is probably the best, as it doesn't constantly badger you to pay the cost of the GR86 for an annual subscription.
Here's the link for the Virgo Leader, carrying mine:
The current position of VIRGO LEADER is at coordinates 34.9014 N / 136.725 E, reported 17 minutes ago by AIS. The vessel is en route to the port of Nagoya and expected to arrive there on Apr 19, 2 AM. The vessel VIRGO LEADER (IMO: 9273894, MMSI 431814000) is a Vehicles Carrier built in 2004 (20...
shipfix.com
Marine Traffic seems to update a little more frequently, and - if you zoom out a bit - can scramble your mind with the sheer number of ships out there on the rolling deep:
MarineTraffic Live Ships Map. Discover information and vessel positions for vessels around the world. Search the MarineTraffic ships database of more than 550000 active and decommissioned vessels. Search for popular ships globally. Find locations of ports and ships using the near Real Time ships...
www.marinetraffic.com
They probably have apps. Hope this helps!