[rogerbinns]

Do you mean different passwords for different services (eg a specific password for Apple email versus a different password for iTunes store?) or that you want access to individual apps password protected?

For the latter Android has the concept of multiple users but only on tablets. It isn't that useful as you can't for example create limited access guest accounts, only full blown ones. And software can't be made accessible the new users unless they create a google account in order to access the play store, even if already installed. It also turned off face recognition for me.

The one thing Android did get right (but not perfect) is having a central account manager. Any service can add itself - for example the Github and Dropbox apps do. Any app (with permissions) can request access to accounts that require user interaction to confirm. However the app does not get a password, but instead a token that has to be periodically renewed.