Note: Before using True Key Instant Log on your iPhone or iPad, make sure you've enabled the True Key extension. [Learn how to here.]
Here's how to instantly log in to your favorite sites without typing passwords on iOS:
1) When on the site you'd like to log in to, tap the Share button.
2) In the Share menu, tap the True Key icon.
3) Sign in to your True Key profile.
4) Tap the login you'd like to use.
5) Let Instant Log In do the rest.
So there you go. That's how you let the True Key app log you in to a website without typing passwords.