For diary purposes, I'd suggest DayOne for iOS/Android and Journaley, a compatible program for PC. Journaley is free and open-source; DayOne is not (though I'm sure someone has an APK somewhere). Source: over 1 year ago

There's even an unofficial open-source PC version of DayOne called Journaley. Apparently, there was also an old version called Day One Classic (but other than the old iOS version on my iOS 7 iPad going by that name, and an import option within Day One, I don't have any more info on it). Source: almost 3 years ago

Leantime (https://leantime.io). It connects strategy boards to execution and is focused on being really easy to use. Source: 12 months ago

I don't know if these are multi-tenant projects but you could certainly explore them: leantime.io and openproject.org. Source: about 1 year ago

We're using Leantime (https://leantime.io) for this. It's really straight forward so I don't think they would need to fuss going into other areas to manage a task. Source: about 1 year ago

Leantime (https://leantime.io) does everything you just mentioned and gives you a little more room to grow if you need it. The claim is to be for the “non-project manager” so good for non-technical teams or teams looking for something to get in and get out of. Source: about 1 year ago

Deck is very minimal and not really suited for anything beyond simple, personal stuff, in my opinion. As far as self-hosted, my favorite is still Kanboard, which has a lot of plugins and themes to choose from. Leantime is good too and a bit different. I also like Vikunja and Wekan. Source: about 1 year ago