You can book tickets easily. However, some filters are missing such as "maximum number of changes" or a way to extend the time at a particular station. I also could not upload tickets bought on the CFl.lu. The timetable is more basic than the one on CFL GO. The "station board" times are not available for every station (e.g, Italy) and there is only a very limited number of stations plans on the app. The design of the app is also a bit too basic. Real time-time platform changes alert didn't work.