I've got revision, homework, programming, university application stuff, and some virtual training for work to juggle at the moment, so I feel I should get something to timetable it, to ensure that I do an even balance.

I run Linux, FreeBSD, Mac OS X 10.6, and (begrudgingly) iOS; and I also have access to Waydroid, Wine, and Darling.

Can anyone suggest some free and open-source software, preferably a web app or iOS app?