Hey, kijubi works. I booked a ticket for the California Academy of Sciences. If you buy the ticket at the gates, they cost 35, but Kijubi sold the adult tickets at 27. I got the student version at 22! Its amazing how much cheaper it was. And they are totally legit.
I purchased the ticket at 1am in the morning on the day I planned to visit, yet I got the voucher in just 15 minutes, which worked perfectly.