I have found vthe following helpfull.
AIS Marine Traffic
ALL available FREE in the MARKET PLACE,
CAUTION ...MY GPS on the phone does NOT work beyond 10-12 miles out at sea.
PLEASE DO NOT rely totally on the phone as your only marine aid.
I have two independant GPS systems that function beyond the 10-12 mile range they are Garmin H72 handheld andf I have an ASUS 10.5" notebook with 10hrs battery that has bluetooth GPS electronic charts.
I also carry full paper charts for ALL the areas I sail and always will.
Safety first :-)
Passsage Plan, Plan It. Plot It. Check It. Add Some Bolt Holes ...Now Check It Again.