What Makes A Good Password Manager?
The good password managers will provide password sharing as an in-built feature, making it easy to share passwords and other relevant information from directly within the application. Some providers will even feature zero knowledge password sharing, enabling users to share passwords in an encrypted form.
Good password managers key characteristic
Encryption
Stored login credentials should always be stored in an encrypted form, using peer reviewed, heavily tested, strong encryption, so that even if the device used to store the passwords is stolen the thief is unlikely to be able to recover passwords.
Secure resource usage
A number of possible vulnerabilities involving unsecured resource usage are possible. Using secure memory that will not be written to a page file or swap partition on disk guards against the danger of a decrypted password being dumped onto the disk where it can be recovered later by a malicious security cracker.
Self-contained functionality
A lot of software is not written with absolute data security in mind, and it often should not be written that way if the intended functionality of the application presents no need for such security.
Usability
Quick, simple, and easy use of the day-to-day functionality of the password manager is important for ensuring that the password manager actually gets used regularly.
Verifiable design
This is especially true of something like a password manager, which manages the data used to access other applications that also need to manage data securely. To ensure that the software is trustworthy, but verifiably the same as the source code used to produce the actual executable program itself.
Conclusion
These five criteria are of fairly universal value for a general-purpose for good password manager, and should probably be considered by everyone designing a password manager or selecting one for personal use.