Please, forgive me if this is old news to many of you, but I recently discovered how useful my iWatch is for navigation on my bike.
Before staring my ride, I put the destination into the Maps app on my iPhone, then put the phone in my pocket. After that, i get turn-by-turn directions from the Maps app on my iWatch.
It helps to position the iWatch on the inside of your left wrist for easier viewing while riding. If you have an iWatch give it a try.