Cloud applications can be used from the web, mobile or desktop.
Which applications do you use for e.g. calendar, tasks, notes?
mobile: k9, conversations, husky, jerboa, gitnex, nextcloud sync, mumla, davx5 (+ fossify calendar) installed but rarely used: jitsi meet, NC talk, tasks.org
desktop: Thunderbird, dino, vscodium, nextcloud sync, mumble