A free app for Android, by Oxen Project.
In Session, you can send private messages directly to anyone. Just pick a contact, choose a subject, and then you're done. You can even send it to multiple contacts at once. The best part is that it's so easy to use, and it's available on all your devices, so you can access it from anywhere. And when you do, it'll be saved for a few seconds, so you can read it in the future.
And when you do have a message for someone, it can be saved directly to their contact list. This makes it really easy to keep in touch with people.
