zncoder

Agree with the mouse-click part. I made this addon to make container a little bit easier to use, https://addons.mozilla.org/en-US/firefox/addon/confiner/. Every page is opened in an ephemeral container. But you can easily make the container for a specific site persistent.

LastPass is hard to use for me, so I wrote my own,

https://addons.mozilla.org/en-US/firefox/addon/passcell/ https://chrome.google.com/webstore/detail/passcell/mjbndaapn...

All encryption/decryption is done inside the browser, as you can verify the source code, https://github.com/zncoder/passcell.