Hiya Dawn!
Thanks for bringing your question to us here at planDisney! I'm so excited for you to spend four days at the Happiest Place on Earth! It sounds like you're already well prepared for your visit and have purchased tickets and added Genie+ to them. Make sure you also have
reservations for the days of your visit as well.
To answer your question, there is no fee attached for each day of use for a
Magic Band+ at the Disneyland Resort. They can be purchased either on
shopdisney.com or at
various locations throughout the Disneyland Resort. Once purchased, all
features are completely free to use. You'll be able to scan your Magic Band+ when entering the Parks and using Lightning Lanes!
You are correct that your Magic Band+ is linked to the
Disneyland Mobile App. In the app, press the three horizontal lines on the bottom right, select Magic Band+, then follow the instructions to link the device to your app. You will also need to link your tickets to your Magic Band+.
I love having my Magic Band+ with me with I visit the Disneyland Resort. It's way more convenient for me as opposed to taking out my phone. I love using it for
Star Wars: Batuu Bounty Hunters in Galaxy's Edge. And here's a fun tip: pay attention to your Magic Band+ as you exit the Haunted Mansion!
Dawn, I hope you find this helpful and that you thoroughly enjoy your trip to the Disneyland Resort! Please feel free to approach us again at planDisney if there is anything else we can do to assist you!
Have a Magic Day!
-Al