MDE app vs browser

So my husband has a smart phone but I made a voluntary return to a flip phone… yes a flip phone… a couple years ago. I’m planning on digging up an old iPhone to carry with me in the parks and use when my husband is off playing golf. I know the Lines app will work just fine, but I’m pretty sure the IOS on the old iPhone will be too outdated to download the MDE app. So, my question:

  1. Has anyone used the MDE website in a phone’s browser and found it fairly easy or difficult to use?
  2. Obviously I’m most concerned about my ability to book fast passes. . . .so can anyone comment on that particular capability?

The alternative is for my husband and I to switch phones while he is off playing golf and I stay in the parks. Just looking at an option that doesn’t involve me commandeering his iphone.

The only downside to that is the Wifi in the parks is, well … suckage. I had to switch off Wifi many times and use my cell data to get a connection.