So the other day I hit this article [1] on planet.kde.org about KDE Itinerary, an application that can store your boarding passes and offer some additional services, such as calendar integration or notifications in case your destination has a different socket type, they drive on the left side, etc. It seemed quite useful and some parts are novel. Maybe there is a future for phones with just free software.
[1] https://www.volkerkrause.eu/2018/08/25/kde-itinerary-overvie...