The blue wires running into the front turn signals are for the running lights, and are on whenever the ignition is on. I used them to switch a relay, so I draw power from the battery but only when the running lights are on. Plus I have replacement turn signals, so the blue wire was cut and hanging loose anyway.
But I am running heated grips and a heated vest also, which is close to 7 amps, so the relay is a necessity. If you are just doing a GPS or phone charger, tapping the blue wire directly should be fine.