A combination of pass (or QtPass) to securely manage credential files from multi-platform desktop systems, Password Store for Android to securely manage credential files from a smartphone, Dropbox for multi-platform access to the credential files, two redundant YubiKey 4's with a USB OTG adapter (or YubiKey NEO's for NFC access) to securely store your OpenPGP private keys, and OpenKeychain for Android to manage your OpenPGP public keys and securely utilize the OpenPGP private keys on your YubiKeys. This is relatively inexpensive at ~$80 per user with no hardware expiry or recurring costs other than support. It works best with a tech-savvy user base. Otherwise, training and adoption may be a nightmare and not worth your time.
We're using 1Password. Sharing various passwords, documents, and licenses between different groups is built-in, so it works well for our needs.
Both Okta and 1Password are officially supported tools at Buffer
to piggyback on this question, does anyone use passbolt [0]? I am considering giving it a look and wanted to know if anyone has experience with it, good or bad.