It’s about time, after the criticism of the first versions of Gmail for iOS (not without reason, because it was buggy), it seems that Google development team is reacting to correct some faults i.e. asking for the password every few minutes. Apart from fixing random bugs Google team also added one of the most requested features : support for the notification center .
According to Google team >>
we’ve improved the login process to allow you to stay logged into the app for as long as you’d like. You can still choose to sign out of your account, but you won’t be automatically logged out after a certain period of time has elapsed.
We’ll continue to improve the app, and we’re looking forward to bringing you more features in future releases, including support for multiple accounts.