I’ve been using matrix for quite a while now and I’m very happy with it.
The thing to be aware of though is that it takes quite a bit of work to get started, but once you’ve got it up and running it doesn’t need much coddling. It’s got video calling built into it now and can be entirely web based if you want it to be. I have all of my signal, WhatsApp and SMS messages being brodged over through it which is handy. I’ve also got a discord bridge set up which will bring all DMs and let’s me bridge any of the servers I want to bring over.
it’s been my one app for communicating with anyone that wants to talk to me on any IM platform I use, as well as any of the federated rooms and spaces I want to access from other home servers I want to work with.
Edit: I also recently added authentication via oidc which was great as now I don’t need to worry about passwords as I just authenticate with passkeys on most of my self hosted services.
I’ll throw another recommendation behind Karakeep. The fact I can share a page fromy mobile browser or use a browser extension on a laptop/desktop is excellent.
Another great thing for me is the oidc support so I can log in without passwords and rely on my Pocket ID instance and log in using a passkey. (Authelia, Authentic, Keycloak and similar identity providers would work too)