To me offline is more important than open source for an app like this. Sustainability without being another app that demands monthly payments is also importan

To me offline is more important than open source for an app like this. Sustainability without being another app that demands monthly payments is also important to me (there are some really nice examples of apps that play their freemium game excellently out there. Agenda on iOS come to mind as an example as does Manic Time on PC. I own both.)