A password manager does not encrypt or sign mails.
Sorry, I wasn't clear. I use last pass to transfer my private key to the PGP app on my iPad (and elsewhere) (as opposed going through Dropbox or whatever).
Relies upon trusting last pass and trusting the iPad of course, both of which are questionable.
They could be compromised, but they claim all data is encrypted locally before being sent to their servers. I have not verified that claim.