Image via Be My Eyes
The app is free, anonymous, and available 24/7. Anyone can join as a volunteer or end user. There's no commitment when joining, so for sighted people, this is a great way to make the world better just a few minutes at a time. Its creators report over 270 thousand help sessions, with over 500 thousand sighted users helping 38 thousand blind ones.
One caveat: Because anyone can join, blind users should avoid revealing sensitive data like credit card numbers to strangers.
Be My Eyes for Android [Google Play]