Account security is a tough issue for a lot of people. It's a constant balancing act between having a stronger system to keep out would-be invaders while also making it convenient enough that users won't reject it. After Google began offering its own 2-step verification system, several other services adopted the same mechanism and opt-in model for people that wanted more than a single password protecting their personal data. This generally left users with Google's Authenticator app, which got the job done, but it lacked features and languished on an early Holo dark design.
Google Authenticator, an important security tool that enables 2-step verification for your Google account, has racked up over 250,000 downloads over its lifetime, which is no small feat for any app in the Play Store. However, a few days ago, that version (previously available here) all of a sudden became obsolete and was consequently silently deleted.
Its replacement, which can be found here, bears version 2 (2.15 to be exact) and offers the following changelog: