The times are displayed for two stops; Home Close (Wolvercote) and Magdalen St Stop G3 (City Centre).
Data is derived from the the Oxontime (http://www.oxontime.com) website, rather than timetables. This should ideally give a more accurate indication that timetables. It can occasionally be misleading, for example the rare occasions that Oxford Bus Company decides to turn a late-running bus round at Wolvercote roundabout.
The app is free and simple to use; it is a small download, with minimal dependencies/requirements - in contrast to many other apps, it does not request any unnecessary permissions, just those needed to connect to the internet to download the tracking information.