My preference is through the website on a PC. Second options would be through the web site via aTablet. The APP would be my last choice.
Same advice for making changes. I find the web site provides more options.
I have never been able to grab a later issued (after the 60 day mark) FP (Wishes or Fireworks) through the APP if I had 3 pciked already. This is real easy on the website, but I find it impossible on the APP. I think the bug lies in the fact that typical rerturn times are 60 minutes, but these other events are around 20 minutes. So I think the APP is not able to identify them as a replacement.