There are some apps you just don't want your kids to use, even if they otherwise have free run of your smartphone. And Android phones currently have no feature to accommodate that.
Having multiple user accounts on a single device essentially lets you lock certain apps behind a password. Unless your kids, co-workers or other snoopers know the password to your account, they're not getting into anything you don't want them to.
This feature debuted on Android tablets in 2013, but Google has waited until now to put it on smartphones too.
Just don't forget your password
However it's unfortunately unclear exactly when or how multiple user accounts will arrive on Android phones, despite this Google project member's promise that it will arrive "as a a part of the next public build."
Does that mean the next public build of the current public release of Android - which would be Android KitKat - or of Android L, the new version launching this year?
We've asked Google to clarify, and we'll update here if we hear back.
Until then don't get too excited about all the things you can do on your phone when you're guaranteed to be the only person who can access certain apps.