Switching Google Accounts
You can change the Google email that you use with Lantern by resetting Lantern and going through the initial setup sequence.
As awesome as it is to watch Lantern connections crossing the globe, most of the time you will probably have Lantern running without the network map visible.
Select Show Lantern from the Lantern icon in the Status Bar
Next, reset Lantern and go through the setup process again. Resetting Lantern clears all saved information since your last setup.
Click the Settings icon.
Click Reset.
A message will appear asking you to confirm that you want to reset Lantern.
'As for signing in to Lantern with a different account, you actually have to go into Settings and click Reset. That will take you back to Lantern's initial setup sequence, giving you the chance to log in with a different Google account. Note that on OS X, Lantern shares your Google login state with Safari for Lantern's login step, so if you're already signed in to Google in Safari as a different account from the one you want to use with Lantern, when you get to Lantern's sign in step, you'll already be logged in to Google as that account. But that Google page does give you the ability to sign in as a different account to use with Lantern, you just have to look for it.'