If you're using two-step authentication for your Google account, you'll want to pick up the latest version of the Authenticator app, which brings a new time syncing feature to ensure correct codes are generated. Previously, if the app's internal clock went too out of sync with Google's, the Authenticator would generate incorrect codes. The new syncing feature remedies this by allowing users to sync the clocks through a new settings page.
With an app as crucial as the Google Authenticator, you'll want to make sure you're always up to date. This one's a manual update, so head to the "My apps" menu in the Google Play Store to grab the new version.