i had to purchase the birnbaums physical book from
amazon as i couldn't find the kindle edition anywhere, so i got both the disneyland, wdw, and wdw food guide delivered to my front door. the disneyland one is a little out of date (obviously) as it was published last year and obviously doesn't incorporate any of the planned rehabs to cars land/princess fantasy faire etc but some of the little insider tips and especially the section on food/dining etc i found really informative, although they do push the staying onsite bit pretty hard, which i found a little offputting.
the wdw one is just amazing

i highly recommend, but unfortunately i had to go old school and get the physical books

although... good for reading on the bus to make going to work more appealing.