Cool new United feature notifies you if your preferred seat becomes available
When booking (or managing) a flight on the mobile app, you'll be able to request your desired seat while browsing the seat map.
For instance, if you're booking just a few days before departure and only middle seats are left, you can set an alert to be notified if a window or aisle seat becomes available.
The app will also allow you to opt into notifications for exit rows and bulkhead (first-row) seats.
If your desired seat choice becomes available, the app will automatically notify you and prompt you to process the seat change.
I'm guessing those of us with ExpertFlyer or similar subscriptions will absolutely hate this as it will make it much harder to snipe a plum seat that opens up before others notice it, but the general public will be happy with this.