In terms of functionality and features, I'm really happy with the app. However, there are a few things that I wish they'd change.
For instance, if I exit out of the app for even a millisecond, I get the "United Data Services Not Available" if I am in the middle of looking up a reservation or otherwise clicking something. I then have to repeat the process.
On Delta's app the reservation data (assumedly) is embedded into the app while on UAL app there is a bit of a wait to load the reservations and to change seats. Occasionally the reservation will not load and I have to repeat the process again.
It's also very puzzling that the app is incapable of showing GPU/RPU data. What's the issue here?
Delta's app seems to be much faster and more streamlined.
That being said, united.com is a total cluster. If the same people who designed that are now redesigning the app, then yeah, not good news!