Can I recommend the MyFlights app. It allows you to add amadeus/sabre booking (so ok for BA ticketed bookings) and constantly monitors them. If anything gets changed including flight times, seat numbers, flight numbers etc. you get a notification on your phone and an email which highlights the change.

You can also add and view booking on their website as well.

http://www.myflightsapp.com/

It is a good way of knwoing if your booking has changed instead of waiting for am email from BA or noticing it on your BAEC page.