Really? Guest mode is a standard feature since Lollipop, but that just logs you into a completely blank account without any installed apps or user data. You can

Really? Guest mode is a standard feature since Lollipop, but that just logs you into a completely blank account without any installed apps or user data. You can switch Google accounts, but that's a multi-tap process that can't be activated directly from the lock screen. Second Space isn't unique in functionality, but it's exceptionally slick in execution.