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From Gray Goo Labs:
Factor2 is an aggressively simple multi-factor authenticator that works out-of-the-box with most major websites that support 2 factor authentication*. No accounts to sign up for. No weird online services. Just your keys stored on your phone. Nothing else.Plus, Touch ID support, a Today widget, and a Safari extension make using your keys easier than ever.Thousands of websites support time-based one-time passwords for added security. These websites sync with Factor2 by displaying a special barcode to scan. When logging in to a website synced with Factor2, you'll be asked for your regular password, and then also for a special code (usually 6 numbers), generated by Factor2 and valid only for a few minutes.This scheme dramatically increases your login security. Now bad guys need to steal not only your password (something you know), but also your phone (something you physically have) to pretend to be you.* Factor2 supports most time-based one-time passwords (based on the RFC 6238 standard), and can scan Google-Authenticator style QR codes (based on Google's "otpauth://totp" URL protocol). Together, these are by far the most common standards used on the web for multi-factor authentication.
[NEW IOS 8 FEATURES] Touch ID support: Individual keys can be protected with Touch ID. Just open the key and tap settings. Safari action extension: easily use your codes in Mobile Safari to log in to protected website.[NEW] Tapping Hide Keys collapses shrinks the list items, so you can see more labels on one screen[FIXED] The wrong keys will no longer be displayed in some circumstances while quickly scrolling the main list during a key change. Toggling "Use Bold Numbers" preference while app is running no longer truncates some code numbers while animating. The swipe-back gesture is detected reliably even when code-change animation is running.