There is a free plan for 1password. Since we already use 1Password, it seems an obvious choice.

• You must be an owner of your team account to apply. Don't have an account? Start a 14 day trial.
• To decrease the chances of getting locked out of your account, invite at least one other person to your team and add them to the Owners group.
• Apply by completing this form and opening a new issue in this repository.
• Move all necessary credentials to new team vault