I wrote an online password exchange app. It improves security when sending passwords via email/IM. The way the app works is that you send a link that allows the user to view the password. That link will then expire within a set time frame. The user can also delete the entry from the database after viewing.
The app is open source and freely available on GitHub. You should be able to get your own instance running within a few minutes.
I’m aware that there are more secure ways for sending passwords (i.e. PGP). From my experience these are usually not feasible when working with non-technical folks. This app is an attempt to improve security at least a bit by not having passwords in your chat history or emails.
You are welcome to use my instance at your own risk but it would be better to set up your own instance and not trust some random guy on the internet.
The app is written in PHP using the Silex framework and Doctrine DBAL. I’m happy to accept pull requests if anyone has some improvements.