Hi, thank you for the plugin.
I am authenticating from external database with sha512 hashed passwords using "Other" field and the following line as the hash code:
$password2 = hash('sha512', $password);
It gives me the ability to share common credentials between WordPress, Openfire and Dovecot. Took me quite some time though to figure out if I needed quotes around password (no) and semicolon at the end (yes). Perhaps a few examples about "Other" hashing possibilities in FAQ would make this great and surprisingly unique plugin more accessible to us sysadmins.