What are some open-source software you'd like everyone to know about?

https://reddthat.com/post/18847149

KepassXC for PC and KeepassDX for Android phones.

I personally would recommend it over Bitwarden since with Bitwarden you NEED internet to access your passwords, and even if is open source, i canmot trust it, security breaches can happen in any time, hsving your vault locally stored helps a lot.

There are more but i can’t Remember them right now.

You can self-host Bitwarden, and sync your vault to your phone. Maybe not an option for everyone since it requires some technical skills, but very doable.
Self-hosting KeePassXC requires installing one package and backing up one file. I expect that requires less technical skill and is doable for more people than to self-host Bitwarden.