I would not underestimate how terrible internal legacy systems at a company like AA could be. It seems completely reasonable to me that this app could save FAs an hour a day or more. And if they're like pilots (who are typically only paid on time from wheels up to touchdown) that is likely an unpaid hour.
What's worse though is that inside the industry there's little awareness of the possibility of doing things differently. Everything is just layers of wrapping around the old system without any abstraction of the processes.
The same is true of flight attendants; they are paid from door close to door open. All that boarding and deplaning time is unpaid.
My source here is that my wife was an FA for many years. She has a couple stories of pilots deliberately not pulling all the way up to the gate if they know they're going to have to wait anyway, purely so the crew can stay on the clock (and it doesn't make any difference to the passengers either way). Though for every one of those instances, there are a hundred of being delayed in the airport or after-boarding-but-before-closed-doors or whatever that ends in hours of unpaid work time.
"it displays information required by crew members to manage their rosters and work lives in a single app.
The app is particularly popular among the large number of ‘reserve’ flight attendants at American Airlines because it gives them more control over their schedules, and the app has other features such as a calculator to make sure crew are working to legal limits."