Found this while wandering around today and thought it was a pretty interesting concept.
From their site:
We’ve always wanted to keep a journal to remember what our days were like, but we never stuck with our journals for too long. We’d write in it for a week or so, and then we’d slowly stop. The relationship just never worked out.
We wanted something that made it really easy to get in the habit of writing a journal. Responding to a daily email seemed like the easiest way, so we created OhLife around that idea.