Manage passwords without storing them
Mnemosyne is a really secure password manager: Passwords are never stored on your device, they are (re)created based on a secret pass phrase that you memorize and the given user name. As long as you remember the pass phrase you can recreate any password for any user name you have created somewhere along the way.
If you need to move to another OS where Mnemosyne isn’t available for then take a look at these alternatives. The software listed below has a similar approach to generate and manage passwords.