Pretty garbage experience. Personal information is near impossible to update or remove (addresses, payments, etc...) It's not linked to the rest of Delta's platforms. Meaning if you check-in online (desktop) the boarding pass isn't automatically shown in your account on the app. The app wants you to check in again, which is a problem if you've already paid for baggage, seats, etc... All in all it's more of a development issue than UX, the app just isn't functioning the way it was designed.