Any of those options should be ok. Truthfully once we get there and we use our phones more as cameras than anything, and our touring plans become guidelines rather than hard and fast plans. If you want to use it though the browser should work ok, but the app works equally well on either iOS or Android. In theory you could use a wifi tablet but that seems like a lot to have to carry around all day and the park wi-fi is dismal at best most days. We always just turn it off and use our plan data.
I got out my son’s 4 year old ipod with a slightly cracked screen. It was all I needed for checking lines and MDE. I also had paper plans printed, but was able to add or change on the fly using the ipod.