At
Disneyland you can only add
Genie+ on the day when you scan into the parks. Some third party ticket sellers do sell tickets with Genie+ included but it is for the length of stay, you either get it for all days or none of the days on the ticket.
I am from Ireland and recently visited Disneyland and used Genie+ on all my days, you can read my trip report
here
I added Genie+ each day straight after scanning into the parks. I walked a bit from the entrance area, found a bench and added it. I used the credit card stored on my Disney account on one day, and a Disney Gift card on other days.
Its very easy to add, you just click on the App and follow the instructions.
One benefit of adding straight after you enter the parks is that Photopass is included and you can get photos at the entrance in front of the train station and at The Hub even if you are in the parks before official park opening.
